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FUEL SYSTEM—1 Group 14 FUEL SYSTEM CONTENTS F U E L PUMP Paragraph Page F u e l P u m p Disassembly Removal Cleaning and Inspection Assembly 7 5 Operation 5 4 Service Diagnosis 1 3 F u e l P u m p T e s t i n g (on Vehicle) Pressure Test V a c u u m Test Volume Test I n l e t V a l v e Test 6 4 (Fuel Pump) BED S E R I E S C A R B U R E T O R S A u t o m a t i c Choke - W e l l Type 19 15 Carburetor A d j u s t m e n t s Accelerator P u m p F a s t Idle A d j u s t m e n t Choke Unloader ( W i d e Open K i c k ) Bowl Vent Valve Adjustment Idle Speed A d j u s t m e n t { C u r b I d l e ) 18 13 Carburetor 15 9 Cleaning C a r b u r e t o r 16 11 Inspection and Reassembly Throttle Body M a i n Body Checking F l o a t S e t t i n g Air Horn 17 11 8 7 14 9 Disassembly Service Diagnosis S e r v i c i n g the C a r b u r e t o r AFB S E R I E S C A R B U R E T O R S A u t o m a t i c Choke ( W e l l T y p e ) Carburetor Adjustments Fast Idle Adjustment Choke Unloader A d j u s t m e n t Accelerator P u m p A d j u s t m e n t Secondary T h r o t t l e Lever A d j u s t m e n t Secondary T h r o t t l e L o c k - O u t A d j u s t m e n t . 24 25 23 24 2 — FUEL SYSTEM A F B S E R I E S CARBURETORS-Continued CONTENTS—Continued Paragraph C a r b u r e t o r Assembly M a i n and T h r o t t l e Body Casting Accelerator P u m p Test I n t a k e Check B a l l Discharge Check Needle A i r Horn-Assembly F l o a t A l i g n m e n t Setting F l o a t Level S e t t i n g Float Drop Setting ~ Page 22 21 - 21 18 - 25 26 ~- 20 18 26 28 Fuel Tank (Imperial) Removal Installation 27 29 F u e l T a n k ( T o w n and C o u n t r y ) Removal Installation 28 30 A d j u s t i n g the A n t i - S t a l l Device 32 36 A d j u s t i n g the R a m M a n i f o l d A F B 2903S Series C a r b u r e t o r Idle Speed and M i x t u r e A d j u s t m e n t ( O n Vehicle) Fast Idle Adjustment (On Vehicle) I n d e x i n g the Choke Piston 33 36 29 32 30 34 31 35 A F B Carburetor — Disassembly A i r H o r n — Disassembly M a i n Body Disassembly Cleaning and Inspection - I d l e Speed A d j u s t m e n t ( C u r b I d l e ) S e r v i c i n g the Carburetor - F U E L TANK F u e l T a n k ( A l l Models Except T o w n and C o u n t r y and I m p e r i a l ) Removal Installation RAM MANIFOLD Ram Manifold - Removal Ram Manifold - Installation S e t t i n g the R a m M a n i f o l d T h r o t t l e L i n k a g e P o s i t i o n i n g the Accelerator Shaft P o s i t i o n i n g the Accelerator Pedal - . - FUEL SYSTEM —3 DATA AND SPECIFICATIONS P 361 Cu. In. V-8 ENGINE 383 C u . I n . V-8 Make - Model 413 C u . I n . V Carter - M-2769S Type Diaphragm N u m b e r o f Valves Driven By 3 . Camshaft P u m p Pressure (Pounds) 3% to 5 [FECIAL TOOLS T109-43 Plug C-3411. Remover Pressure Gauge E DIAGNOSIS 1. FUEL PUMP LEAKS—FUEL b. Leaks i n fuel line or Possible Causes? c. a. Loose housing screws, c. Loose d i a p h r a g m m o u n t i n g plates. e. Frozen gas lines. f. I m p r o p e r l y seating valves. g. V a p o r lock. h. Weak m a i n spring. i. I n c o r r e c t fuel pump, j. Restricted fuel fittings. 2. F U E L PUMP L E A K S — O I L Possible Causes: a. D i r t or r e s t r i c t i o n i n fuel tank. d. W o r n , r u p t u r e d , or t o r n diaphragm. b. W o r n , r u p t u r e d or t o r n diaphragm, d. Loose inlet or outlet line fittings. Cracked or deteriorated p u l l r o d oil seal. filter. b. Loose rocker a r m p i v o t p i n . c. Loose p u m p m o u n t i n g bolts. 4. FUEL PUMP N O I S E d. Defective pump t o block gasket. Possible Causes: 3. I N S U F F I C I E N T F U E L D E L I V E R Y a. Loose m o u n t i n g bolts. b. Scored o r w o r n rocker a r m . Possible Causes: a. V e n t i n t a n k filler neck restricted. also cause collapsed fuel t a n k . ) (This w i l l c. W e a k or broken rocker a r m s p r i n g . 4 — FUEL SYSTEM Group 14 FUEL SYSTEM F U E L PUMP F u e l p u m p Model M-2769S is used on a l l De Soto, C h r y s l e r and I m p e r i a l engines. T h e service procedures f o r t e s t i n g , disassembly, overhaul, cleaning and reassembly o f the fuel p u m p appears below. 5. OPERATION—FUEL PUMP T h e fuel p u m p ( F i g . 1) is d r i v e n b y an eccentric cam (cast i n t e g r a l w i t h the camshaft) t h r o u g h the m e d i u m or a s h o r t push r o d . A s the camshaft rotates, the eccentric cam presses against the push r o d , f o r c i n g the p u m p rocker a r m d o w n . T h i s a c t i o n l i f t s the p u l l r o d and d i a p h r a g m u p w a r d s against the fuel p u m p m a i n s p r i n g , t h u s c r e a t i n g a v a c u u m i n the valve housing, w h i c h opens the i n l e t valves, f o r c i n g fuel i n t o the valve h o u s i n g chamber. On the r e t u r n stroke, the m a i n s p r i n g forces the d i a p h r a g m to the d o w n p o s i t i o n w h i c h closes the i n l e t valves and expels the fuel i n the valve h o u s i n g chamber, t h r o u g h the outlet valve to the fuel filter and the c a r b u r e t o r . t y and a l o w pressure r e a d i n g w i l l result. ( 4 ) Connect a tachometer, t h e n s t a r t the engine and r u n at 500 r . p . m . The r e a d i n g should be f r o m 3% t o 5 p.s.i. The pressure should r e m a i n constant or r e t u r n to zero v e r y , v e r y slowly w h e n the engine is stopped. A n i n s t a n t drop to zero indicates a leaky outlet valve. I f the pressure is too low, a weak m a i n s p r i n g or i m p r o p e r assembly of the d i a p h r a g m m a y be the cause. I f the pressure is too h i g h , the m a i n s p r i n g is too s t r o n g . ROCKER ARM HOUSING ROCKER ARM FOLLOWER SPRING T h e f u e l filter assembly should be changed every 10,000 miles, to i n s u r e h a v i n g a n u n r e s t r i c t e d flow of fuel at a l l times. D O N O T A T T E M P T T O CLEAN. i. — DIAPHRAGM AND PULL ROD ASSEMBLY Mr SCREW ASSEMBLY TESTING FUEL PUMP—(On ¥ e M c l e ) I f the fuel p u m p f a i l s to s u p p l y fuel p r o p e r l y t o the c a r b u r e t o r , the f o l l o w i n g tests should be made before r e m o v i n g the fuel p u m p f r o m the vehicle. VALVE-ASSEMBLY (SERVICED ONLY IN VALVE BODY) VALVE B O D Y - a. Pressure Test SCREW ASSEMBLY I f leakage is n o t apparent, test p u m p f o r pressure, as follows : (1) I n s e r t a "T" fitting i n t h e fuel line at c a r b u r e t o r , as s h o w n i n F i g u r e 2. the •1 AIR DOME \ DIAPHRAGM ( 2 ) Connect a 6 i n c h piece o f hose between t h e " T " fitting a n d gauge C-8411. ( T h e hose should n o t exceed 6 inches. A longer hose m a y collect f u e l and the a d d i t i o n a l w e i g h t w o u l d be added t o the pressure of the p u m p and r e s u l t i n a n inaccurate r e a d i n g . ) ( 3 ) V e n t t h e p u m p f o r a f e w seconds ( t h i s relieves a n y a i r t r a p p e d i n the f u e l c h a m b e r ) . I f t h i s is n o t done, the p u m p w i l l n o t operate a t f u l l capaci- -VALVE ASSEMBLY (SERVICED ONLY IN VALVE BODY) -COVER 60x189 Fig. 1 - F u e l Pump M-2769S (Exploded V i e w ) FUEL SYSTEM —5 a. Removal (1) Remove the p i v o t p i n plug, u s i n g Tool T109- 43. TACHOMETER (ENGINE S P E E D ) 6 INCH MAXIMUM ( 2 ) Disengage t h e rocker a r m follower s p r i n g f r o m the rocker a r m and the r o c k e r a r m housing. ( 3 ) T u r n t h e p u m p on i t s side ( p i v o t p i n hole d o w n ) and t a p g e n t l y t o remove t h e p i v o t p i n . ( 4 ) Disengage t h e rocker a r m f r o m the diap h r a g m p u l l r o d , b y the s l i d i n g r o c k e r a r m o u t o f the housing. Fig. 2—Pressure Testing Fuel P u m p b. Vacuum Test The v a c u u m test should be made w i t h the fuel l i n e disconnected f r o m the c a r b u r e t o r . ( T h i s w i l l a l l o w the p u m p t o operate at f u l l capacity, w h i c h i t m u s t do to p r i m e a d r y c a r b u r e t o r . ) The v a c u u m r e a d i n g should be at least 10" h.g. v a c u u m at 500 r . p . m . w i t h the fuel line disconnected at the c a r b u r e t o r . ( 5 ) Remove t h e screws a t t a c h i n g t h e valve body to the r o c k e r a r m housing. Separate the valve body and r o c k e r a r m h o u s i n g and l i f t out the d i a p h r a g m and p u l l r o d assembly. ( 6 ) Remove t h e screws t h a t a t t a c h t h e valve body to the valve h o u s i n g cover. Separate cover and valve body and remove the outlet a i r dome d i a p h r a g m . b. Cleaning and Inspection ( 1 ) Clean a l l fuel p u m p p a r t s (except d i a p h r a g m ) i n a suitable solvent, t h e n b l o w d r y w i t h compressed air. ( 2 ) Check the condition of t h e valve seats and p a r t s f o r g u m deposits. c. Volume Test The fuel p u m p should supply 1 q u a r t o f fuel i n 1 m i n u t e or less at 500 r . p . m . d. Inlet Valve Test To test the i n l e t valve, connect a v a c u u m gauge on the i n l e t fitting w h i l e the line is disconnected. ( 3 ) I f g u m deposits are found, remove w i t h den a t u r e d alcohol. ( 4 ) I f t h e valves are badly w o r n or damaged, i n stall a complete new valve body assembly. T h e valves are not serviced individually. ( 1 ) S t a r t t h e engine or t u r n over w i t h s t a r t i n g motor. ( 5 ) Inspect t h e d i a p h r a g m f o r cracks, t o r n screw holes or r u p t u r e s . Check the r u b b e r o i l seal on the end o f the p u l l r o d f o r d e t e r i o r a t i o n . ( 2 ) There should be a noticeable v a c u u m present, n o t a l t e r n a t e d b y blowback. ( 6 ) Inspect the o u t l e t a i r dome d i a p h r a g m f o r cracks or d e t e r i o r a t i o n . ( 3 ) I f blowback is present, t h e i n l e t valves are n o t seating p r o p e r l y and should be cleaned, o r a n e w valve body installed. ( 7 ) Inspect t h e rocker a r m f o r scoring or g a l l i n g on the camshaft or push r o d b e a r i n g surface. c. Assembly (Fig. 1) I f the fuel p u m p does not p e r f o r m to the above test requirements, the fuel p u m p should be removed f r o m the vehicle and reconditioned as f o l l o w s : 7. FUEL PUMP DISASSEMBLY (Fig, 1) N O T E : Before disassembling the fuel pump, mark the housings in such a manner that the "Inlet" will be facing the inlet fuel line when reassembled. T h i s is important! (1) the Place t h e airdome d i a p h r a g m i n p o s i t i o n on valve body or filter housing (depending on p u m p ) , w i t h i n l e t passage hole over passage. ( 2 ) A l i g n t h e scribe m a r k s on t h e cover ( o r filter housing, depending on p u m p ) a n d the valve body, t h e n i n s t a l l a t t a c h i n g screws. T i g h t e n securely. ( 3 ) Slide the d i a p h r a g m p u l l r o d up i n t o t h e rocker a r m housing. Place the valve body i n posi- 6 — FUEL SYSTEM t i o n on the d i a p h r a g m w i t h the scribe m a r k s aligned. (Be sure the holes i n the d i a p h r a g m , rocker a r m housing and valve bodies are aligned.) Compress the u n i t together. T h e n i n s t a l l the a t t a c h i n g screws, b u t do not t i g h t e n . N E V E R U S E S H E L L A C OR A N Y OTHER ADHESIVE ON T H E DIAPHRAGM, (4) Slide t h e rocker a r m i n t o t h e housing and gage the d i a p h r a g m p u l l r o d . A l i g n the p i v o t holes i n the a r m w i t h those i n the housing, t h e n s t a l l p i v o t p i n . I n s t a l l new p l u g and d r i v e i n curely. enpin inse- (5) I n s t a l l t h e rocker a r m follower s p r i n g over the tab on the rocker a r m and over the dimple i n the housing. (6) Engage t h e ends of t h e bowl r e t a i n i n g strap i n the slots of the filter housing. T i l t the r e t a i n i n g s t r a p to one side, f a r enough to i n s t a l l the ceramic filter. (7) I n s t a l l a new ceramic filter, s p r i n g and bowl. Center the b o w l , then t i g h t e n the r e t a i n i n g screw securely. ( 8 ) Place the pump i n a vise ( w i t h protector j a w s ) and push on the rocker a r m u n t i l f u l l t r a v e l is reached. H o l d i n t h i s position, w h i l e t i g h t e n i n g the a t t a c h i n g screws. ( T h i s w i l l prevent t e a r i n g of the d i a p h r a g m w h e n the p u m p is i n operation and the p u m p a r m i n its f u l l stroke.) (9) Test t h e fuel p u m p as described previously. BBD S E R I E S C A R B U R E T O R DATA AND SPECIFICATIONS CARBURETOR Type B a l l and B a l l D u a l T h r o a t Model BBD-2923S or BBD-2924S BORE - VENTURI - MAIN METERING 1-9"16" 1-5/16" JET Standard N o . 120-245S No. 120-238S One Size L e a n N o . 120-248S N o . 120-248S Two N o . 120-250S N o . 120-250S Sizes L e a n ADJUSTMENTS F l o a t S e t t i n g ( a t center o f f l o a t s ) Accelerator P u m p (top o f p l u n g e r to a i r h o r n ) Fast Idle 9/32" 1 - f or — 1/64" 1375 to 1425 r . p . m . F a s t Idle S e t t i n g Choke U n l o a d e r .015" ( w i d e open k i c k ) I d l e M i x t u r e ( b o t h screws) I d l e Speed ( c u r b i d l e ) ( w i t h air conditioning) Bowl Vent Valve Setting 1 / 4" 1 f u l l t u r n open ± y 2 500 r . p . m . 575 r . p . m . .060" CHOKE Type Control Setting Well-Automatic Thermostatic Coil On I n d e x Spring FUEL SYSTEM —7 SPECIAL TOOLS T109-287S E l e v a t i n g Legs ( 3 ) T109-288S E l e v a t i n g Legs T109-239 F l o a t Gauge ( 9 / 3 2 " ) ) P a r t of T109-289U (1) T109-44 W i r e Gauge (.015" F a s t I d l e ) T109-22 B e n d i n g Tool T109-31 Choke Unloader Gauge ( % " ) .060" D r i l l (Bowl Vent Valve) T109-213 B e n d i n g Tool S E R V I C E DIAGNOSIS 8. POOH IDLING v. I n t a k e m a n i f o l d leak, Possible Causes: w . I n t e r n a l coolant leak. a. Incorrect a i r idle adjustment. x. L o w b o i l i n g p o i n t fuel ( w i n t e r fuel i n s u m m e r ) . b. Carbonized idle tube or poor seating shoulder. y. L o w grade fuel. Co M a n i f o l d heat control valve stuck. z. I n c o r r e c t valve t i m i n g . d. I d l e air bleed carbonized or o f incorrect size. e. Idle discharge holes plugged or gummed. f. T h r o t t l e body shaft. carbonized or worn throttle g . A i r leak at m o u n t i n g between carburetor and manifold. h. Damaged or w o r n idle needle. i. I n c o r r e c t fuel or float level. j. Choke does n o t completely open. k. Loose m a i n body to t h r o t t l e body screws. 1. 9. POOR PERFORMANCE—MIXTURE TOO LEAN Possible Causes: a. Damaged m a i n m e t e r i n g j e t . b. Damaged t i p or bad top shoulder seat of m a i n discharge j e t . c. V a c u u m p i s t o n w o r n o r stuck, do Incorrect fuel or float level. e. A u t o m a t i c choke n o t operating properly. f. Incorrect fuel p u m p pressure. Carburetor i c i n g . m. D i s t r i b u t o r advance vacuum leak. 10. POOR PERFORMANCE—MIXTURE T O O RICH n. Loose d i s t r i b u t o r base plate bearing. Possible Causes: o. Corroded w i r e ends or d i s t r i b u t o r towers. a. p. Incorrect d i s t r i b u t o r p o i n t gap. b. Excessive fuel p u m p pressure. q. Fouled spark plugs. c. H i g h float or fuel level. r. Incorrect ignition timing. d. Damaged needle and seat. s. I n c o r r e c t spark p l u g gap. e. L e a k i n g float. t. Overheated spark plugs. f. Worn main metering jet. u. Compression n o t w i t h i n l i m i t s . g. S t i c k i n g choke. Restricted a i r cleaner. 8 — FUEL SYSTEM 11. E X C E S S I V E FUEL CONSUMPTION d. W o r n needle valve and seat. Possible Causes: e. L e a k i n g float. f. Excessive fuel p u m p pressure. a. Overloading ( p u l l i n g t r a i l e r s , etc.). b. I m p r o p e r rear axle r a t i o . c. W r o n g speedometer pinion. N O T E : Presence of fuel dye around carburetor gaskets does n o t necessarily denote a leak or a flooding condition. T i g h t e n a i r h o r n a t t a c h i n g screws securely t o correct. d. Brakes d r a g g i n g . e. Detonation or pre-ignition. f. D r i v i n g at excessive speeds. g. L o w t i r e pressure. h. Short t r i p or heavy traffic d r i v i n g . i. D r i v i n g i n snow or m u d . j. D r i v i n g i n high winds. k. Unnecessary use o f accelerator. c. F a u l t y acceleration p u m p discharge ball. 1. S t i c k y choke. d. 13. POOR ACCELERATION Possible Causes: a. Step-up p i s t o n stuck i n down position (lean m i x t u r e at wide open t h r o t t l e ) . b. Accelerator p u m p piston (or p l u n g e r ) leather too h a r d , w o r n or loose on stem. Accelerator p u m p i n l e t check ball f a u l t y . m. I n c o r r e c t i g n i t i o n t i m i n g . e. Incorrect fuel o r float level. n. f. W o r n accelerator p u m p and t h r o t t l e linkage. o. H i g h fuel level i n carburetor. g. A u t o m a t i c choke n o t operating properly. p. Stuck m a n i f o l d heat c o n t r o l valve. h. Carburetor gummed up. q. Fouled spark plugs. i. F a u l t y coil. r. L o w engine compression. j. Loose d i s t r i b u t o r base plate bearing. s. W o r n camshaft lobes. k. D i s t r i b u t o r n o t advancing p r o p e r l y . t. S t i c k i n g valves. 1. Incorrect ignition timing. u. E l e v a t i o n and atmospheric conditions. m. I n c o r r e c t spark p l u g gap. I n c o r r e c t d i s t r i b u t o r advance. v. Restricted t a i l pipe or muffler causing exhaust back pressure. w. I n c o r r e c t valve t i m i n g . 12. CARBURETOR FLOODS OR LEAKS Possible Causes: n. Fouled spark plugs. o. Overheated spark plugs. p. M a n i f o l d heat control valve stuck. q. L o w fuel pump pressure or vacuum. r. Compression n o t up t o specifications. a. Cracked body. s. L o w grade of fuel. b. Defective body gaskets. t. D e t o n a t i o n or p r e - i g n i t i o n . u. I n c o r r e c t valve t i m i n g . c. H i g h float or fuel level. FUEL SYSTEM — 9 C A R B U R E T O R MODELS BBD-2923S OR BBD-2924S 14. SERVICING THE CARBURETOR D i r t , dust, w a t e r and g u m m y deposits are some of the m a i n causes f o r poor c a r b u r e t o r operation. P r o p e r cleaning, however, and i n s t a l l a t i o n of new p a r t s , where required, w i l l r e t u r n the c a r b u r e t o r to its o r i g i n a l l y designed performance. W h e n o v e r h a u l i n g the carburetor, several items of i m p o r t a n c e should be observed to assure a good j o b . A l l p a r t s should be carefully cleaned i n a suitable solvent and inspected f o r damage and wear. Replace questionable p a r t s w i t h N E W ones. Use a i r pressure only, to clear the various orifices and passages. SERVICE PROCEDURES 15. CARBURETOR DISASSEMBLY (Fig. 3) ( 1 ) I n s e r t t h r e e Tool T109-287S and one Tool T109-288S elevating legs t h r o u g h the c a r b u r e t o r t h r o t t l e body stud holes. (These tools are used to protect the t h r o t t l e valves f r o m damage and to p r o vide a suitable base f o r w o r k i n g . ) ( 2 ) Remove the h a i r p i n clip and disengage ACCELERATOR PUMP ARM the fast idle connector r o d f r o m the t h r o t t l e and idle levers. ( 3 ) Remove the h a i r p i n clip and disengage the accelerator p u m p r o d f r o m the t h r o t t l e lever and the p u m p rocker a r m , as shown i n F i g u r e 4. ( 4 ) Remove t h e a i r h o r n r e t a i n i n g screws and l i f t a i r h o r n s t r a i g h t up and a w a y f r o m the m a i n body. D i s c a r d the gasket (2 screws recessed). CHOKE VALVE ACCELERATOR PUMP PLUNGER BOWL VENT SEAL CHOKE PISTON CYLINDER AIR HORN FAST IDLE SCREW IDENTIFICATION TAG FAST IDLE CAM FAST IDLE LEVER - . THROTTLE BODY MAIN BODY ACCELERATOR PUMP ROD < THROTTLE LEVER . fast FAST IDLE CONNECTOR ROD IDLE SPEED SCREW ELEVATING LEG (TOOL) 58x240B Fig. 3—Carburetor Assembly BBD-2923S or BBD-2924S 10 —FUEL SYSTEM —FLOAT STEP UP PISTON .ACCELERATOR PUMP CONNECTOR ROD J •IS FAST IDLE C O N N E C T O R ROD / CENTER HOLE GASKET "i HAIRPIN C U P 58x241A Fig. 4—Removing ©r Installing Fast Idle a n d Pump Rods ( 5 ) Disengage t h e accelerator p u m p plunger f r o m the accelerator p u m p a r m b y p u s h i n g up on b o t t o m of p l u n g e r a n d s l i d i n g p l u n g e r shaft off hook, as s h o w n i n F i g u r e 5. Slide p l u n g e r o u t o f a i r h o r n and remove the compression s p r i n g a n d seat. I f the old p l u n g e r can be used a g a i n o r i f a n e w p l u n g e r is t o be installed, place t h e p l u n g e r i n a j a r o f clean gasoline o r kerosene t o p r e v e n t t h e leather f r o m d r y i n g out. _ _ NEEDLE Ox*— V A L V E r 111 w 58x242 A Fig. 6—Removing or Installing Float w e l l , as shown i n F i g u r e 7. L i f t out t h e step-up p i s t o n s p r i n g . Remove the step-up p i s t o n gasket f r o m the b o t t o m o f t h e w e l l . STEP-UP PISTON STEP-UP RODS STEP-UP PISTON SPRING MAIN ' METERING JETS ( 6 ) Remove t h e fuel i n l e t needle valve, seat and gasket f r o m t h e m a i n body. ( 7 ) L i f t out t h e float f u l c r u m p i n retainer, and l i f t out the floats a n d f u l c r u m p i n , as s h o w n i n F i g u r e 6. ( 8 ) Remove t h e step-up p i s t o n and r e t a i n i n g screw a n d slide the step-up p i s t o n a n d rods o u t o f R E T A I N I N G SCREW 60x102 ACCELERATOR PUMP SHAFT ACCELERATOR PUMP ARM Fig. 7—Removing m Girnsira.ling Step-Up Piston SPECIAL TOOL C H O K E PISTON LINK CHOKE PISTON PLUG 58x246A Fig. 5—Removing or Installing Accelerator Pump MAIN METERING JET > 58x244A Fig. 8—Removing or Installing Main Metering Jets FUEL (9) Remove t h e m a i n m e t e r i n g j e t s a n d gaskets, as shown i n F i g u r e 8. SPARK IDLE T R A N S F E R PORTS A (10) Remove the v e n t u r i cluster idle bleed screws, t h e n l i f t t h e v e n t u r i cluster and gaskets up and away f r o m t h e m a i n body, as shown i n F i g u r e 9. Discard the gaskets. Do not remove the idle orifice tubes or the main vent tubes from the cluster. T h e y can be cleaned i n a solvent and d r i e d w i t h compressed air. (11) I n v e r t t h e c a r b u r e t o r and drop o u t t h e accelerator p u m p discharge check ball. - \ IDLE 16. CLEANING C A I B U R E T O I The recommended solvent f o r g u m deposits is den a t u r e d alcohol w h i c h is easily obtainable. There are other commercial solvents, however, w h i c h m a y be used w i t h satisfactory results. IMPORTANT I f the commercial solvent or cleaner recommends the use of water as a rinse, it should be " H O T . " After rinsing, all trace of water must be blown from the passages with air pressure. I t is further advisable to rinse all parts in clean kerosene or gasoline to be cer- Fig. 9 - R e m o v i n g or Installing Venturi Cluster ADVANCE PORT / IDLE M I X T U R E VALVES SCREWS SPEED r SCREW (13) Remove t h e screws t h a t a t t a c h t h e t h r o t t l e body to the m a i n body. Separate the bodies and discard the gasket. I t is usually not advisable to remove the t h r o t t l e shaft or valves f r o m the t h r o t t l e body, unless wear or damage necessitates the i n s t a l l a t i o n o f new parts. V THROTTLE (12) Remove t h e idle m i x t u r e a d j u s t i n g screws and springs f r o m the t h r o t t l e body. The c a r b u r e t o r n o w has been disassembled i n t o three sub-assemblies, the a i r h o r n , m a i n body and t h r o t t l e body and the components of each disassembled as f a r as necessary f o r cleaning and inspection. SYSTEM—11 .1' Fig. - GASKET ^- 60x104 1 0 — P o r t s in Relation to Throttle V a l v e s tain no trace of moisture remains. Never clean jets with a wire, drill or other mechanical means, because the orifices may become enlarged, making the mixture too rich for proper performance. 17. INSPECTION A N D 1EASSEMBLY a. Throttle Body (1) Inspect t h e t h r o t t l e shaft and t h r o t t l e body for excessive wear. I f either or b o t h are w o r n t o the p o i n t w h e r e the c a r b u r e t o r operation w i l l be affected, replace as r e q u i r e d . D u r i n g m a n u f a c t u r e , the location of the idle t r a n s fer p o r t and the spark advance c o n t r o l p o r t s t o t h e t h r o t t l e valve, is carefully established f o r one p a r t i c u l a r assembly ( F i g . 1 0 ) . I f a new shaft should be installed i n an old, w o r n t h r o t t l e body, i t w o u l d be v e r y u n l i k e l y t h a t the o r i g i n a l r e l a t i o n s h i p of the p o r t s to the valves w o u l d Fig. 1 1-lnstalling Throttle V a l v e s 12 — F U E L SYSTEM be obtained. C h a n g i n g the relationship o f the valves t o the p o r t s w o u l d adversely affect n o r m a l car opera t i o n between the speeds o f 15 and 30 miles per h o u r . I f i t has been determined, however, t h a t a new shaft o r valves is to be installed, adhere to the f o l l o w i n g instructions. ( 2 ) M a r k t h e p o s i t i o n o f t h e t h r o t t l e valves i n t h e bores. Be sure the i d l e speed screw is backed off. ( 3 ) Remove t h e screws t h a t hold t h e t h r o t t l e valves t o the shaft and slide the valves out o f the bores. CAUTION These screws are staked on the opposite side and care should be used a t r e m o v a l so as n o t t o .break off i n the shaft. ( 4 ) Slide t h e t h r o t t l e shaft and lever out o f t h e body. ( 5 ) I n s t a l l new t h r o t t l e shaft and lever. ( 6 ) I n s t a l l t h r o t t l e valves i n t h e i r respective bores ( w i t h the valve numbers t o w a r d the m a n i f o l d flange). I n s t a l l new screws b u t do n o t t i g h t e n . H o l d the valves i n place, w i t h the fingers pressing on the h i g h sides o f the valves, as shown i n F i g u r e 1 1 . T a p the valves l i g h t l y w i t h a s c r e w d r i v e r t o seat i n the t h r o t t l e bores. T i g h t e n the screws securely and stake b y squeezing w i t h p l i e r s . ( 7 ) I n s t a l l t h e idle m i x t u r e screws and springs i n the t h r o t t l e body. ( T h e tapered p o r t i o n m u s t be s t r a i g h t a n d smooth. I f the tapered p o r t i o n is grooved or r i d g e d , new idle m i x t u r e screws should be i n s t a l l e d to insure h a v i n g correct idle m i x t u r e control.) D O N O T U S E A S C R E W D R I V E R . T u r n STEP-UP RODS MUST MOVE FREELY 60x106 Fig. 13—Step-Up Rod Free Play t h e screws l i g h t l y against t h e i r seats w i t h t h e fingers. Back off one f u l l t u r n f o r approximate adjustment. b. Main Body (1) I n v e r t the m a i n body and place a new gasket i n p o s i t i o n and place the t h r o t t l e body on the m a i n body and a l i g n . I n s t a l l screws and t i g h t e n securely. ( 2 ) I n s t a l l t h e accelerator p u m p discharge check b a l l i n the discharge passage and check the accelera t o r p u m p system; fuel i n l e t and discharge check balls as f o l l o w s : ( 3 ) Pour clean gasoline i n t o t h e carburetor bowl, a p p r o x i m a t e l y / i n c h deep. Remove the p u m p p l u n g e r f r o m the j a r o f gasoline, flex the leather several times, t h e n slide d o w n i n t o the p u m p c y l i n der. Raise the p l u n g e r and press l i g h t l y on the p l u n g e r shaft to expel a l l a i r f r o m the p u m p passage. l 2 ( 4 ) U s i n g a s m a l l clean brass r o d , hold t h e discharge check b a l l d o w n f i r m l y on i t s seat. A g a i n raise the p l u n g e r and press d o w n w a r d . N o fuel should be e m i t t e d f r o m either the i n t a k e o r discharge passage, as shown i n F i g u r e 12. I f any fuel does e m i t f r o m either passage, i t i n d i cates the presence o f d i r t o r a damaged check b a l l . Check the passage again and repeat test. I f leakage is s t i l l evident, i n s t a l l a new check ball. The fuel i n l e t check b a l l is located a t the b o t t o m o f the p l u n g e r w e l l and should r a t t l e freely w h e n the carburetor is shaken. 58x249B Fig. 12—Testing Accelerator Pump Intake a n d Discharge Check Balls ( 5 ) I n s t a l l new gaskets on t h e v e n t u r i cluster, and i n s t a l l i n p o s i t i o n i n the m a i n body. (Refer t o F i g . 9 ) . I n s t a l l the idle bleed screws and t i g h t e n securel y . Test p u m p discharge b y pressing p u m p p l u n g e r FUEL SYSTEM— 13 d o w n . T w o fine streams o f fuel should be forced f r o m the cluster. I f e i t h e r s t r e a m is r e s t r i c t e d or d i v e r t e d , remove cluster and reclean. A f t e r test, p o u r the f u e l f r o m the b o w l and remove p u m p plunger. ( 6 ) I n s t a l l t h e m a i n m e t e r i n g j e t s and gaskets. T i g h t e n securely. (Refer to F i g . 8 ) . ( 7 ) Before i n s t a l l i n g t h e step-up piston, be sure the step-up rods are able to move freely, each side of the v e r t i c a l p o s i t i o n , as shown i n F i g u r e 13. The step-up rods m u s t be s t r a i g h t and smooth. FROM TOP O F PUMP SHAFT TO BOTTOM O F AIR HORN ( 8 ) Slide t h e step-up p i s t o n gasket d o w n i n t o posit i o n i n the p i s t o n w e l l , t h e n i n s t a l l the step-up p i s t o n s p r i n g , step-up p i s t o n and rods. C a r e f u l l y guide t h e step-up rods i n t o the m a i n m e t e r i n g j e t s . (Refer to F i g . 7 ) . I n s t a l l the r e t a i n i n g screw and t i g h t e n securely. Check p i s t o n f o r free operation i n the well. THROTTLE VALVES SEATED ^ 3 . , . A step-up p i s t o n stuck i n the U p p o s i t i o n w i l l cause a r i c h m i x t u r e a t p a r t t h r o t t l e , whereas a p i s t o n stuck i n the D o w n p o s i t i o n w i l l cause a lean m i x t u r e at w i d e open t h r o t t l e and poor acceleration. c. Checking Float Setting (1) I n s t a l l t h e floats and f u l c r u m p i n . ( 2 ) Assemble t h e fuel inlet needle valve, seat and gasket a n d i n s e r t i n p o s i t i o n i n the m a i n body. T i g h t e n securely. ( I f the needle valve is r i d g e d or b a d l y w o r n , i n s t a l l a new needle valve and seat assembly.) ( 3 ) U s i n g Tool T109-239 or a " T " scale, check t h e float s e t t i n g , as shown i n F i g u r e 14. There should be 9 / 3 2 " f r o m top o f the c r o w n o f each float t o t o p FLOAT UP HELD AGAINST NEEDLE VALVE ^ %^ ^ ^^^^^^ \ FLOAT G A U G E 60x107 71 4—Checking FAST IDLE SCREW O F F FAST IDLE CAM 58x255B Fig. 15—Measuring Accelerator Pump Travel of the m a i n body. E a c h float m u s t be adjusted t o t h i s s e t t i n g a n d should not touch the sides o f the b o w l . I n s t a l l float f u l c r u m p i n r e t a i n e r . d. A i r Horn ( 1 ) Check the freedom o f t h e choke mechanism i n the a i r h o r n . The shaft and p i s t o n m u s t float free to operate c o r r e c t l y . I f the choke p i s t o n sticks i n the c y l i n d e r , pierce the welsh p l u g and remove p l u g and p i s t o n . Clean t h o r o u g h l y a n d r e i n s t a l l p i s t o n . I n s t a l l new p l u g . ( 2 ) Remove accelerator p u m p p l u n g e r f r o m gasoline, slide compression s p r i n g and s p r i n g seat over shaft. I n s t a l l assembly i n a i r h o r n a n d engage w i t h accelerator p u m p a r m . (Refer t o F i g . 5 ) . (3) Place a new gasket on t h e m a i n body, and i n s t a l l the a i r h o r n . I n s t a l l a t t a c h i n g screws and t i g h t e n securely. ( W h e n i n s t a l l i n g a i r h o r n , be sure the leather on the p l u n g e r does n o t w r i n k l e or f o l d back.) (4) Engage t h e accelerator p u m p r o d w i t h t h e p u m p rocker a r m and i n s t a l l loose end i n the center hole o f t h r o t t l e lever. (Refer t o F i g . 4 ) . I n s t a l l h a i r p i n clip to secure. • Fig. § ¥l©at Setting ( 5 ) Engage the f a s t idle connector r o d i n t h e fast idle lever and t h r o t t l e lever. I n s t a l l h a i r p i n clip t o secure. (Refer t o F i g . 4.) 18. CABBURETOl ADJUSTMENTS I t is v e r y i m p o r t a n t t h a t the f o l l o w i n g adjustments are made on a reconditioned c a r b u r e t o r and i n the sequence l i s t e d : 14 —FUEL SYSTEM . UNLOADER GAUGE iHROTTLE VALVE b#lf LIGHT FINGER PRESSURE ' A G A I N S T CHOKE VALVE T i l THROTTLE VALVES IN WIDE OPEN POSITION ^ ^ ^ ^ ^ ^ ^ ' ' . ^ ^ FAST IDLE C A M \ INDEX MARK FAST IDLE ADJUSTING S C R E W 58x252 A 58x254B Fig. 16—Checking Fast Idle Setting Fig. 18—Checking Choke Unloader Setting a. Accelerator Pump (1) Back off t h e idle speed a d j u s t i n g screw. Open the choke valve so t h a t the t h r o t t l e valves can be completely seated i n the bores. Be sure t h a t the p u m p connector r o d is i n s t a l l e d i n the center hole of the t h r o t t l e lever. ( 2 ) H o l d i n t h i s position, and i n v e r t t h e carburet o r . Slide w i r e gauge Tool T109-44 .015" between t h e t h r o t t l e valves and the bore (side opposite p o r t s ) . T i g h t e n the fast idle a d j u s t i n g screw u n t i l a s l i g h t d r a g is f e l t as gauge is b e i n g w i t h d r a w n , as shown i n F i g u r e 16. ( 2 ) Close t h e t h r o t t l e valves t i g h t l y . Measure t h e distance between the top o f t h e a i r h o r n and the end o f p l u n g e r shaft, as s h o w n i n F i g u r e 15. T h i s measurement should be 1 " ± o r — 1/64 i n c h . ( 3 ) A g a i n , i n v e r t t h e carburetor a n d open t h e valves to w i d e open position. Close the t h r o t t l e valves and the choke valve t i g h t l y . ( 3 ) To adjust p u m p t r a v e l , bend t h e p u m p connector r o d , u s i n g Tool T109-213, a t t h e l o w e r angle of r o d , u n t i l correct t r a v e l has been obtained. ( 4 ) Release t h e choke valve only. T h i s again posit i o n s the f a s t idle cam to fast idle. The i n d e x m a r k on the cam should s p l i t the center o f the f a s t idle screw shank, as shown i n F i g u r e 17. b. Fast Idle Adjustment (1) Open t h e t h r o t t l e valves and hold t h e choke valve i n the f u l l y closed p o s i t i o n . Close t h e t h r o t t l e valves. T h i s w i l l p o s i t i o n the f a s t idle cam t o the fast idle p o s i t i o n . I f an adjustment is necessary, bend the t a n g on the choke shaft lever, u s i n g Tool T109-22 u n t i l the i n d e x m a r k on the cam indexes w i t h the a d j u s t i n g screw. INDEX MARK 58x253B Fig. 17—Fast Idle Index Mark A l i g n e d • - ~ 58x256B Fig. 19—Bending Fast Idle Lever Tang FUEL SYSTEM—15 c. Choke Unloader (wide open kick) ( 1 ) H o l d t h e t h r o t t l e valves i n t h e wide open posit i o n . I n s e r t Tool T109-31 ( o r a d r i l l shank) between the upper edge o f the choke valve and the i n n e r w a l l of the a i r h o r n , as shown i n F i g u r e 18. ( 2 ) W i t h a finger l i g h t l y pressing against t h e valve, a s l i g h t d r a g should be f e l t as gauge is b e i n g w i t h d r a w n . I f an a d j u s t m e n t is necessary, bend the t a n g on the fast idle lever, u s i n g Tool T109-22, as shown i n F i g u r e 19 u n t i l correct clearance has been obtained. C H O K E ROD DUST S E A L WASHER COVER CALIBRATION IOCK M A R K S \ NUT d. Bowl Vent Valve Adjustment ( 1 ) W i t h the t h r o t t l e valves held closely, i t should be possible to i n s e r t a .060" d r i l l shank between the b o w l vent valve and the a i r h o r n . (2) I f an adjustment is necessary, bend t h e short t a n g on the vent valve o p e r a t i n g lever, u s i n g Tool T109-22 u n t i l correct clearance has been obtained. e. Idle Speed Adjustment (curb idle) The idle speed a d j u s t m e n t is made after the b u r e t o r has been installed on the engine. THERMOSTATIC C O I L ^ J ^ t ^ SPRING AND H O U S I N G ' -INDEX MARK 57P55 Fig. 20—Well Type Automatic Choke Unit be clean and move freely. O t h e r t h a n an occasional cleaning, the choke requires no s e r v i c i n g . I t is v e r y i m p o r t a n t , however, t h a t t h e choke c o n t r o l u n i t w o r k freely i n the w e l l and at the choke shaft. car- ( 1 ) W i t h the t h r o t t l e valves closed and t h e choke valve w i d e open (engine at n o r m a l o p e r a t i n g t e m p e r a t u r e ) adjust the idle speed screw to give 500 r . p . m . u s i n g a tachometer, (575 r . p . m . on a i r condit i o n equipped c a r s ) . ( 2 ) A d j u s t the idle m i x t u r e screws u n t i l the engine operates smoothly. Recheck the tachometer and again adjust the idle screw to give the correct engine r . p . m . 19. AUTOMATIC C H O K E — W E L L TYPE To f u n c t i o n p r o p e r l y , i t is i m p o r t a n t t h a t a l l p a r t s Move the choke movement on the choke u n i t should C H O K E U N I T is a t t e m p t to r e p a i r F i g . 20.) r o d up and d o w n to check f o r free p i v o t . I f the u n i t binds, a new be installed. T H E W E L L T Y P E serviced as an assembly. D o n o t or change the index s e t t i n g . (See W h e n i n s t a l l i n g the w e l l t y p e choke u n i t , be cert a i n t h a t the coil h o u s i n g does not contact the sides of the w e l l i n the i n t a k e m a n i f o l d . A n y contact at t h i s p o i n t w i l l affect choke operation. D o not l u b r i c a t e any p a r t s o f the choke or the cont r o l u n i t . T h i s causes an accumulation o f d i r t w h i c h w i l l result i n b i n d i n g of the choke mechanism. 16 — FUEL SYSTEM AFB S E R I E S CARBURETOR DATA AND SPECIFICATIONS CARBURETOR Type Model (automatic t r a n s m i s s i o n ) 4 Barrel Downdraft AFB-2927S, 2950S AFB-2968S AFB-2903S T H R O T T L E BORE Primary Secondary MAIN VENTURI Primary Secondary LOW SPEED Primary . . 1-7/16" 1-11/16" 1-3/16" 1-5/16" 1-3/16" 1-9/16" JET No. 67-.032" ADJUSTMENTS Accelerator P u m p S e t t i n g (top of plunger to a i r h o r n ) Choke Unloader ( w i d e open k i c k ) F a s t Idle A d j u s t m e n t F a s t Idle Speed ( r p m ) Idle Speed A d j u s t m e n t ( r p m ) ( w i t h air conditioning) ( r p m ) Secondary T h r o t t l e Lever A d j u s t m e n t Secondary T h r o t t l e Lock-Out A d j u s t m e n t F l o a t S e t t i n g (gasket to top of floats) Float Drop Idle M i x t u r e ( b o t h screws-turns open) A u t o m a t i c Choke U n i t S e t t i n g * 1-7/16" 1-9/16" N o . 67-.035" 7/16" y±" .020" 1775-1825 500 550* 19/64" .020" 7/32" %" 1-2 2 Notches R i c h N o . 65-.035" 7/16" A " .010" ***1475-1525 **725-750 *550 19/64" .020" 9/32" %" 1-2 1 Notch Rich l 550 r p m w i t h the transmission i n " D " or " R " and the a i r c o n d i t i o n i n g compressor " o n " . ** 725 to 750 r p m and constant w i t h the t r a n s m i s s i o n i n n e u t r a l ( N ) and the a i r c o n d i t i o n i n g compressor " o n " ( i f so equipped). ***On R a m Charge De Soto A d v e n t u r e r and 1375-1425 on the Chrysler Model C300F. S P E C I A L TOOLS C-3400 T109-287S T109-22 T109-29.... T109-31 T109-41 T109-58 T109-59 T109-106 T109-126 T109-200 T109-213 ... . R e p a i r Stand E l e v a t i n g Legs B e n d i n g Tool W i r e Gauge (.020" and .030") ( F a s t I d l e ) .Gauge (Choke U n l o a d e r ) B e n d i n g Tool ( F a s t Idle E n d U n l o a d e r ) Screwdriver B i t Screwdriver B i t F l o a t Gauge ( 7 / 3 2 " ) .Float Gauge ( 9 / 3 2 " ) W i r e Gauge (.010" and .012") ( F a s t I d l e ) B e n d i n g Tool FUEL SYSTEM—17 CHOKE VALVE STEP-UP PISTON A N D 58x275 A STEP-UP PISTON AND ROD COVER PLATE (2) CHOKE PISTON LINK ACCELERATOR PUMP CONNECTOR LINK FUEL INLET C O N N E C T I O N -f-V ACCELERATOR PUMP SHAFT MODEL NUMBER AND DATE STAMPED O N BOSS (AT CENTER O F CARBURETOR) SECONDARY THROTTLE OPERATING LEVER . ^JLT, *~ 7 PUMP C O N N E C T O R ROD IN CENTER HOLE O F ARM / PRIMARY THROTTLE SHAFT ARM (OUTER) DISTRIBUTOR VACUUM FITTING THROTTLE OPERATING ROD PRIMARY THROTTLE SHAFT ARM (INNER) PRIMARY THROTTLE SHAFT D O G Fig. 21—Carburetor A s s e m b l y 58x276 A 18 — F U E L SYSTEM AFB SERIES CARBURETOR MODELS AFB-2927S, 2950S, 2968S, 2903S The new A F B ( a l u m i n u m f o u r b a r r e l ) c a r b u r e t o r contains m a n y new features, some o f w h i c h are a new location f o r the step-up rods and pistons. The step-up rods, pistons and springs are accessible f o r service w i t h o u t r e m o v i n g the a i r h o r n , o r the carb u r e t o r f r o m the engine. The v e n t u r i assemblies ( p r i m a r y and secondary) are replaceable and contain m a n y o f the c a l i b r a t i o n points f o r b o t h the h i g h and l o w speed system. One fuel b o w l feeds b o t h the p r i m a r y and secondary nozzles on the r i g h t side w h i l e the other fuel b o w l takes care o f the p r i m a r y and secondary nozzles on the left side. T h i s provides i m p r o v e d performance i n c o r n e r i n g , quick stops and acceleration. A l l the m a j o r castings of the c a r b u r e t o r are a l u m i n u m , w i t h the t h r o t t l e body cast i n t e g r a l w i t h the m a i n body. T h i s allows an overall h e i g h t r e d u c t i o n i n the carburetor. The section c o n t a i n i n g the accele r a t o r p u m p is t e r m e d the p r i m a r y side o f the carb u r e t o r . The rear section is the secondary. The five conventional systems are t w o float systems, t w o l o w speed systems ( p r i m a r y side o n l y ) , t w o h i g h speed systems, one accelerator p u m p syst e m and one automatic choke control system. 20. SERVICING THE CARBURETOR D i r t , dust, w a t e r and g u m m y deposits are some of the m a i n causes f o r poor carburetor operation. H o w ever, proper cleaning and the i n s t a l l a t i o n of new parts, w h e r e required, w i l l r e t u r n the carburetor to i t s o r i g i n a l l y designed performance. W h e n o v e r h a u l i n g the A F B carburetor, several items o f importance should be observed to assure a good j o b . The c a r b u r e t o r should be carefully disassembled and a l l p a r t s should be cleaned i n a suitable solvent and inspected f o r wear or damage. A i r pressure only should be used to clean the v a r i o u s orifices and channels. Replace questionable p a r t s w i t h new ones. SERVICE PROCEDURES 2 1 . DISASSEMBLING THE AFB CARBURETOR (Fig. 21) tons and rods out of the a i r h o r n , as shown i n F i g u r e 22. Remove the step-up p i s t o n springs. ( 1 ) Place t h e c a r b u r e t o r assembly o n repair stand Tool C-3400 or T-109-287S e l e v a t i n g legs. ( 6 ) Remove t h e ten screws t h a t attach the a i r STEP-UP PISTON AND ROD ( 2 ) Remove t h e h a i r p i n clip t h a t attaches the f a s t idle connector r o d to the choke lever. Disengage r o d f r o m lever, t h e n s w i n g r o d at a n arc u n t i l i t can be disengaged f r o m the fast idle cam. STEP-UP PISTON SPRING ( 3 ) Remove t h e retainer and s p r i n g t h a t holds t h e t h r o t t l e connector r o d i n the center hole o f t h e accelerator p u m p a r m . Remove the h a i r p i n clip t h a t attaches the l o w e r end o f r o d i n the p r i m a r y t h r o t t l e shaft lever. Disengage r o d f r o m a r m and lever, t h e n remove f r o m c a r b u r e t o r . ( 4 ) Remove the screws a t t a c h i n g p i s t o n and r o d cover plates. the step-up N O T E : H o l d c o v e r d o w n w i t h a finger to p r e v e n t t h e p i s t o n a n d r o d s f r o m flying o u t . (5) L i f t off the plates and slide the step-up pis- COVER PLATES 58x277 -~ STEP-UP PISTON r \ STEP-UP ROD Fig. 22—Removing or Installing Step-Up Pistons a n d Rods FUEL h o r n to the m a i n body ( 1 screw i n hole i n a i r h o r n ) . L i f t a i r h o r n s t r a i g h t up and a w a y f r o m the m a i n body. N O T E : W h e n r e m o v i n g a i r h o r n , u s e c a r e so a s n o t to bend o r d a m a g e t h e floats. ( 7 ) Remove t h e accelerator p u m p plunger lower s p r i n g f r o m the p u m p c y l i n d e r . SYSTEM—19 PRIMARY VENTURI ( C H O K E SIDE) SECONDARY VENTURI (CHOKE SIDE) PRIMARY VFNTURI (PUMP S I D E ) . SECONDARY VFNTURI (PUMP SIDE) ^ '* a. Disassembling the A i r Horn Place the a i r h o r n i n an i n v e r t e d p o s i t i o n on the bench (to p r o t e c t the floats). (1) U s i n g a suitable tool, remove t h e float f u l c r u m pins (left and r i g h t ) and l i f t t h e floats up and out of bosses on a i r h o r n . N O T E : I t i s s u g g e s t e d t h a t t h e float o n t h e p u m p side be m a r k e d s o t h a t t h e floats c a n be r e - i n s t a l l e d in their respective positions. ( 2 ) Remove t h e t w o needle valves f r o m t h e i r respective seats, a f t e r m a r k i n g the one on the p u m p side f o r identification. U s i n g a w i d e blade screwd r i v e r , remove the needle valve seats. Be sure each needle valve is r e t u r n e d t o i t s o r i g i n a l seat at reassembly. ( 3 ) Remove the h a i r p i n clip t h a t holds the accele r a t o r p u m p connector l i n k i n the p u m p a r m and p l u n g e r shaft. Disengage l i n k f r o m p u m p a r m a n d shaft. Slide the accelerator p u m p p l u n g e r and s p r i n g out o f the a i r h o r n . Remove the a i r h o r n t o m a i n body gasket and discard. ( 4 ) Place the accelerator p u m p plunger i n a j a r of clean gasoline or kerosene, to p r e v e n t the leather f r o m d r y i n g out. ( 5 ) Remove t h e fuel i n l e t fitting and filter screen f r o m the a i r h o r n . DISCHARGE CHECK NEEDLE (IN HOLE) ACCELERATOR / PUMP CYLINDER ' '' |L l\ f*; f%lf^^W y S E C O N D A R Y JET (2) A PRIMARY J E T (2) 58*2/8 Fig. 24—Removing or Installing Main Metering Jets ( 6 ) U s i n g a p r i c k punch, pierce t h e welch p l u g and remove i t f r o m the end o f choke p i s t o n c y l i n d e r . Remove cotter p i n t h a t attaches the p i s t o n l i n k t o the choke valve lever. Slide choke p i s t o n and l i n k out o f cylinder. b. M a i n B o d y D i s a s s e m b l y (1) Remove t h e screws t h a t a t t a c h the accelerat o r p u m p j e t h o u s i n g to the m a i n body. L i f t out the j e t housing and gasket, as shown i n F i g u r e 23. D i s c a r d the gasket. I n v e r t the m a i n body and d r o p out the discharge check needle f r o m the discharge passage. ( 2 ) U s i n g Tool T109-58, remove t h e m a i n meteri n g jets ( p r i m a r y side), as shown i n F i g u r e 24. N O T E : T h e p r i m a r y and secondary main metering j e t s a r e not interchangeable. I t is very important t h a t t h e s e j e t s be i n s t a l l e d i n t h e i r r e s p e c t i v e locat i o n s i n t h e m a i n body a t r e a s s e m b l y . GASKET PRIMARY VENTURI (PUMP SIDE) h?IMAKY VENTURI C H O K E SIDE / / '4 si- MODEL NUMBER A N D DATE STAMPED O N BOSS <** • 'f ' A 58x283 Fig. 23—Removing or Installing Accelerator P u m p Jet Housing Fig. 25—Removing or Installing Primary Venturi 20 — FUEL SYSTEM SECONDARY VENTURI PUMP SIDE GASKET PUMP JET HOUSING ^ SECONDARY VENTURI (CHOKE SIDE) y h IDLE DISCHARGE PORTS PRIMARY THROTTLE VALVES ACCELERATOR PUMP INTAKE PASSAGE CHOKE SIDE OF CARBURETOR PUMP SIDE OF CARBURETOR SECONDARY VENTUF NOZZLE BLEEDER TUBE PRIMARY VENTURI ^ ( 5 ) Remove the screws t h a t attach the secondary v e n t u r i (choke and p u m p side) to the m a i n body. L i f t the secondary v e n t u r i assemblies s t r a i g h t up and away f r o m the body, as shown i n F i g u r e 26. NOZZLE \ BLEEDER TUBE DO NOT REMOVE TUBES R O M VENTURI 58x284 Fig. 26—Removing or Installing Secondary Venturi ( 3 ) A g a i n using Tool T109-58, remove the m a i n m e t e r i n g jets (secondary side), as shown i n F i g u r e 24. ( 4 ) Remove the screws v e n t u r i (choke and p u m p L i f t the v e n t u r i s t r a i g h t m a i n body, as shown i n gaskets. t h a t a t t a c h the p r i m a r y side) to the m a i n body. up and a w a y f r o m the F i g u r e 25. D i s c a r d the N O T E : The v e n t u r i assemblies are not interchangeable, side f o r side and m u s t be re-installed i n t h e i r o r i g i n a l location a t reassembly. VA INCH BIT CHECK BALL SEAT PLUG ^ 58x287 Fig. 28—Ports in Relation to Throttle V a l v e s MAIN BLEED TUBE % IDLE TUBE IDLE TRANSFER PORTS 58x286 Fig. 27—Removing or Installing Accelerator Pump Intake Check Ball Seat ( 6 ) I n v e r t the m a i n and t h r o t t l e body casting, and remove the accelerator p u m p i n t a k e check b a l l p l u g . U s i n g Tool T109-59, s c r e w d r i v e r b i t , remove the check b a l l seat, as shown i n F i g u r e 27. A g a i n i n v e r t the body casting and drop out the i n t a k e check ball. ( 7 ) Remove the t w o idle m i x t u r e a d j u s t i n g screws and springs f r o m the t h r o t t l e body p o r t i o n of the m a i n casting. The c a r b u r e t o r now has been disassembled i n t o t w o units, the a i r h o r n and m a i n and t h r o t t l e body casting. The component p a r t s of each have been disassembled as f a r as necessary f o r cleaning and inspection. I t is usually not advisable to remove the t h r o t t l e shafts or valves, unless w e a r or damage necessitates the i n s t a l l a t i o n of new p a r t s . D u r i n g the manufact u r e of the carburetor, the location of the idle t r a n s fer ports and the idle discharge p o r t s to the valve is carefully established f o r one p a r t i c u l a r assembly, as shown i n F i g u r e 28. The valves are m i l l e d to give the proper p o r t relation. I f new t h r o t t l e shafts should be installed i n an old, w o r n body, i t w o u l d be v e r y u n l i k e l y t h a t the o r i g i n a l relationship of these p o r t s to the valves w o u l d be obtained. A v e r y slight change i n the p o r t r e l a t i o n s h i p to the valves w o u l d adversely affect n o r m a l c a r b u r e t o r operation, between the speeds of 15 and 30 miles per hour. I t is recommended t h a t i f the t h r o t t l e shafts are excessively w o r n , t h a t a new c a r b u r e t o r be installed. FUEL SYSTEM I f the t h r o t t l e valves, however, have become nicked, b u r r e d or damaged, new valves m a y be installed, p r o v i d i n g the f o l l o w i n g i n s t r u c t i o n s are carefully followed. N O T E : The screws t h a t a t t a c h the t h r o t t l e valves are staked on the opposite side and care should be used i n r e m o v a l so as not to break the screws i n the t h r o t t l e shaft. Remove the staked p o r t i o n of the screws w i t h a file. Remove the screws t h a t attach the p r i m a r y t h r o t t l e valves to the t h r o t t l e shaft and slide valve (or valves) o u t o f the bores. Remove the screws t h a t a t t a c h the secondary t h r o t t l e valves to the t h r o t t l e shaft and slide valve (or valves) out of bores. T h e p r i m a r y valves and secondary valves are not interchangeable and should be k e p t separate i n order t h a t each m a y be r e t u r n e d to i t s respective bore. (See F i g . 29.) c. Cleaning and Inspection 22. a. —21 CARBURETOR ASSEMBLY M a i n a n d Throttle B o d y C a s t i n g (1) Slide t h e p r i m a r y t h r o t t l e valve (or valves) i n t o t h e i r respective bores, i n s t a l l new screws, b u t do not t i g h t e n . Be sure the idle speed a d j u s t i n g screw is backed out. H o l d the valves i n place w i t h fingers (fingers pressing on the h i g h side o f the v a l v e s ) . ( 2 ) Tap t h e valves l i g h t l y w i t h a screwdriver to seat i n the bores. H o l d i n g the valves i n t h i s posit i o n , t i g h t e n the screws securely. Stake screws b y squeezing w i t h pliers. ( 3 ) I n s t a l l the t w o idle m i x t u r e a d j u s t i n g screws and springs i n the t h r o t t l e body p o r t i o n of the casting. The tapered p o r t i o n m u s t be smooth and s t r a i g h t . I f the tapered p o r t i o n is grooved or r i d g e d , a new idle m i x t u r e a d j u s t i n g screw should be i n stalled to insure h a v i n g correct idle m i x t u r e control. N O T E : D o n o t u s e a screwdriver. The recommended solvent f o r g u m deposits is den a t u r e d alcohol. There are other other commercial solvents, however, w h i c h m a y be used w i t h satisf a c t o r y results. The a d j u s t m e n t should be made w i t h the fingers. T u r n the idle m i x t u r e a d j u s t i n g screws l i g h t l y against t h e i r seats and back off one f u l l t u r n f o r an a p p r o x i m a t e adjustment. IMPORTANT I f t h e commercial solvent or cleaner recommends the use o f a w a t e r rinse, i t should be " H O T . " A f t e r r i n s i n g , a l l trace of w a t e r m u s t be blown f r o m the passages w i t h a i r pressure. I t is f u r t h e r advisable to rinse a l l p a r t s i n clean kerosene or gasoline to be c e r t a i n no trace of moisture remains. Never clean j e t s w i t h a w i r e , d r i l l , or other mechanical means, because the orifices m a y become enlarged, m a k i n g the m i x t u r e too r i c h f o r proper performance. ( 4 ) Place new secondary v e n t u r i gaskets i n posit i o n , i n s t a l l the secondary v e n t u r i ( p u m p and choke side) b y l o w e r i n g s t r a i g h t d o w n on gaskets. I n s t a l l a t t a c h i n g screws and t i g h t e n securely. s SECONDARY VAIVE (THICK) ^^^K ^^^^ • N O T E : B e s u r e a l l t h e m e t e r i n g holes a n d v e n t t u b e s a r e c l e a n , i n b o t h t h e p r i m a r y a n d secondary v e n t u r i . ( 5 ) Place new p r i m a r y v e n t u r i gaskets i n position, t h e n i n s t a l l the p r i m a r y v e n t u r i ( p u m p and choke side) b y l o w e r i n g s t r a i g h t d o w n on the gaskets. (See F i g . 2 5 ) . I n s t a l l a t t a c h i n g screws and t i g h t e n securely. ( 6 ) I n s t a l l the p r i m a r y and secondary m a i n meteri n g jets, u s i n g Tool T109-58. (See F i g . 24.) T i g h t e n j e t s securely. ( 7 ) I n v e r t t h e carburetor and i n s t a l l the accelerat o r p u m p i n t a k e check b a l l . I n s t a l l seat and t i g h t e n securely, u s i n g Tool T109-59 ( F i g . 2 7 ) . I n s t a l l screw p l u g and t i g h t e n securely. b. Accelerator P u m p Test (1) Pour clean gasoline i n t o t h e carburetor bowl ( a p p r o x i m a t e l y / i n c h deep). Remove the accelerat o r p u m p p l u n g e r f r o m the j a r o f gasoline. F l e x the leather several times, t h e n slide onto the p u m p cylinder. l 2 PRIMARY VALVC-" Fig. 29—Throttle V a l v e Identification (2) I n s t a l l t h e accelerator pump discharge check 22 —FUEL SYSTEM needle i n the discharge passage. Raise the p u m p p l u n g e r and press l i g h t l y on the p l u n g e r shaft t o expel a i r f r o m the p u m p passages. U s i n g a s m a l l clean brass r o d , hold the discharge check needle firmly on i t s seat. A g a i n raise the p l u n g e r and press d o w n w a r d . N o fuel should be e m i t t e d f r o m either the i n t a k e o r discharge passage. (8) I f fuel does e m i t f r o m the i n t a k e passage, disassemble t h e i n t a k e check b a l l and reclean the passage. F u e l leakage a t the discharge check needle indicates the presence o f d i r t or - a damaged check needle. Clean a g a i n and t h e n i n s t a l l a new check needle. Retest f o r leakage. ( 4 ) I f either the i n t a k e check ball or discharge check needle leaks a f t e r above test and service fix, a t t e m p t t o reseat as f o l l o w s : c. Intake Check Ball Remove the screw p l u g , gasket, b a l l seat and b a l l f r o m the b o t t o m o f the t h r o t t l e body flange. I n s t a l l a new b a l l and b a l l seat. I n s t a l l screw p l u g and n e w gasket and retest as described p r e v i o u s l y . d. Discharge Check Needle ( 1 ) W i t h t h e discharge check needle installed, i n sert a piece o f d r i l l r o d d o w n on the needle. L i g h t l y t a p the d r i l l r o d w i t h a h a m m e r to f o r m a new seat. Remove and discard old needle and i n s t a l l a new one. Retest as described previously. I f the service fix does not correct the condition, a new c a r b u r e t o r m u s t be installed. ( 2 ) I n s t a l l t h e 'accelerator p u m p discharge check needle, j e t h o u s i n g and gasket. I n s t a l l h o u s i n g a n d a t t a c h i n g screws. T i g h t e n screws securely. (3) Press, d o w n on t h e accelerator p u m p plunger THESE SURFACES MUST BE PARALLEL. AIR HORN FUEL BAFFLE . FLOAT GAUGE GASKET IN PLACE 57 x 802 A Fog, 3 ii-Checking Float Height shaft and as the p l u n g e r is being depressed, a clear s t r a i g h t stream should e m i t f r o m each j e t . i f t h e streams are i d e n t i c a l ( i f either one is d i v e r t e d o r r e s t r i c t e d ) a new accelerator p u m p j e t housing should be installed. A f t e r test, p o u r the gasoline f r o m the c a r b u r e t o r b o w l and remove p u m p plunger. e. Air Horn Assembly (1) Slide t h e fuel inlet screen i n t o t h e fuel line fitting, t h e n i n s t a l l fitting i n a i r h o r n . T i g h t e n securely. ( 2 ) Check t o see i f t h e leather on t h e accelerator p u m p p l u n g e r is h a r d , cracked or w o r n . I f any s i g n o f w e a r o r d e t e r i o r a t i o n is evident, i n s t a l l a new p l u n g e r assembly. ( 3 ) Slide the accelerator plunger i n t o a i r h o r n , and i n s t a l l the accelerator p u m p l i n k . I n s t a l l the ret a i n i n g h a i r p i n clip t o secure. ( 4 ) Place a new a i r h o r n t o m a i n body gasket i n position on the a i r h o r n and i n s t a l l the float needle valve seats. (Re sure each needle seat a n d needle is reinstalled i n i t s o r i g i n a l p o s i t i o n . ) (5) Slide t h e r i g h t and left floats i n t o position i n the a i r h o r n and i n s t a l l the float f u l c r u m p i n s . N O T E : Be sure the marked float is installed on the pump side of the air horn. ( 6 ) A f t e r t h e floats have been installed, check t h e float alignment, level a n d d r o p settings as f o l l o w s : f. Float Alignment Setting (1) S i g h t d o w n t h e side o f each float shell t o det e r m i n e i f the side o f the float is p a r a l l e l t o t h e outer edge o f the a i r h o r n casting, as s h o w n i n F i g ure 3 0 . I \/ MINIMUM CLEARANCE WITHOUT BINDING- 57 x 801 Fig. 30—Checking Float Alignment ( 2 ) I f t h e sides of t h e float are n o t i n a l i g n m e n t w i t h the edge o f casting, bend the float lever b y a p p l y i n g pressure t o t h e end o f the float shell w i t h the fingers w h i l e s u p p o r t i n g the float lever w i t h the thumb. FUEL SYSTEM — 2 3 N O T E : T o avoid damage to t h e float, apply only enough pressure t o bend the float lever. ( 3 ) A f t e r a l i g n i n g the floats, remove as m u c h clearance as possible between t h e a r m s o f the float lever a n d the lugs on the a i r h o r n . T o do t h i s , bend the float lever. T h e a r m s o f the float lever should be p a r a l l e l as possible t o the i n n e r surfaces o f the lugs or the casting. g. Float Level Setting (1) W i t h t h e a i r h o r n i n v e r t e d , t h e a i r h o r n gask e t i n place and the float needle seated, slide float gauge Tool T109-106 ( 7 / 3 2 " ) between t h e t o p o f t h e float (at outer end) and t h e a i r h o r n gasket, as shown i n F i g u r e 3 1 . F l o a t should j u s t t o u c h gauge. ( 2 ) Check t h e other float i n t h e same manner. I f an a d j u s t m e n t is necessary, bend the float a r m u s i n g T o o l T109-22, u n t i l correct clearance has been obtained. A f t e r b e n d i n g a r m , recheck the float alignment. h. Float Drop Setting (1) H o l d i n g t h e a i r h o r n i n a n u p r i g h t position, measure the distance f r o m the top o f the floats (outer end) t o the a i r h o r n gasket, as s h o w n i n F i g u r e 32. T h i s measurement should be % i n c h . I f an a d j u s t m e n t is necessary, bend the stop tabs on the float levers u n t i l the correct d r o p s e t t i n g has been obtained. Bend t h e t a b t o w a r d s the needle seat to lessen the d r o p , or a w a y f r o m t h e seat to increase the d r o p . ( 2 ) A f t e r t h e floats have been checked and adjusted, continue t o assemble the c a r b u r e t o r as f o l lows: ( 3 ) Place t h e accelerator p u m p p l u n g e r lower s p r i n g i n the p u m p c y l i n d e r , t h e n l o w e r the a i r h o r n c a r e f u l l y d o w n on the m a i n body. GASKET IN PLACE \\ 57 x 803 A STOP TABS Fig. 32—Checking Float Drop cylinders, followed b y the step-up pistons and stepup rods. I n s t a l l the cover plates and a t t a c h i n g screws w h i l e h o l d i n g the step-up pistons d o w n i n position. T i g h t e n screws securely. ( 6 ) Slide t h e choke p i s t o n i n t o i t s c y l i n d e r i n t h e a i r h o r n , g u i d i n g the l i n k i n t o the slot i n the choke valve lever. A l i g n hole, t h e n i n s t a l l a t t a c h i n g cotter p i n . Place a n e w welsh p l u g over c y l i n d e r opening and secure b y r a p p i n g w i t h a hammer. Check the fit of the choke valve i n a i r h o r n . The valve should be evenly spaced on a l l sides. Loosen screws and rep o s i t i o n i f necessary. ( 7 ) Engage t h e t h r o t t l e connector r o d w i t h t h e p r i m a r y t h r o t t l e shaft lever and i n s t a l l h a i r p i n clip. Slide the flat washer over the other end o f r o d and engage w i t h the accelerator p u m p a r m . I n s t a l l ret a i n e r s p r i n g and r e t a i n e r securely. ( 8 ) Engage t h e lower end. o f t h e fast idle connector r o d w i t h the fast idle cam, t h e n s w i n g i n a n arc t o lock i n cam. Slide other end o f r o d i n t o the choke shaft lever and secure w i t h h a i r p i n clip. WIRE GAUGE- CAUTION Be sure the fuel baffles on the a i r horn, slide down in front (bowl side) of the float chamber baffles, or the air horn will not index correctly with the main body and can cause the floats to hang up. Be sure the leather on the plunger does not curl or wrinkle. Accelerator pump operation will be affected if this precaution is not observed. ( 4 ) I n s t a l l t h e (10) a i r h o r n a t t a c h i n g screws and t i g h t e n securely. ( T h e t w o l o n g screws should be installed i n the holes t h a t are located a t the a i r cleaner m o u n t i n g surface. T h e 1 i n c h screw a t the f r o n t and the l / i n c h a t t h e r e a r . ) FAST IDLE ADJUSTING S C R E W 'KIT INDEX MARK O N C A M . HIGH STEP O F FAST IDLE C A M ' l 2 (5) Slide the step-up p i s t o n springs i n t o t h e p i s t o n C H O K E VALVE TIGHTLY C L O S E D — - - ^ 58x289 A Fig. 33—Checking Fast Idle Adjustment 24 —FUEL SYSTEM 23. CARBURETOR ADJUSTMENTS UNLOADER G A U G E ':•./• INCH) The f o l l o w i n g adjustments should be made w i t h the c a r b u r e t o r on t h e bench f o r ease o f w o r k i n g , and should be made i n t h e f o l l o w i n g o r d e r : a. Fast Idle Adjustment (1) W i t h t h e choke valve held t i g h t l y closed and c a r b u r e t o r i n v e r t e d , t i g h t e n the fast idle a d j u s t i n g screw ( o n t h e h i g h step o f t h e fast idle c a m ) u n t i l w i r e gauge Tool T109-29 (.020 i n c h ) can be i n serted between the p r i m a r y t h r o t t l e valve a n d t h e bore (side opposite idle p o r t ) , as shown i n F i g u r e 33. T h e index m a r k o n t h e fast idle c a m should be i n d i r e c t line w i t h t h e fast idle screw shank. ( 2 ) I n v e r t t h e carburetor a n d open t h e t h r o t t l e valves t o w i d e open p o s i t i o n . Close t h e choke valve t i g h t l y a n d t h e n close t h e t h r o t t l e valves. Release the choke valve. T h i s w i l l p o s i t i o n the fast idle c a m to fast idle. T h e i n d e x m a r k o n t h e c a m should s p l i t the center o f t h e fast idle a d j u s t i n g screw, as s h o w n i n F i g u r e 34. ( 3 ) I f an a d j u s t m e n t is necessary, bend t h e fast idle connector r o d a t t h e angle, u s i n g Tool T109-213, u n t i l t h e i n d e x m a r k on t h e c a m indexes t h e fast idle a d j u s t i n g screw. b. Choke Unloader Adjustment .. \ V ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ M j I 58x291 . LIGHT FINGER PRESSURE AGAINST CHOKE V A L V I B E N D UNLOADER LIP T H R O T T L E VALVES WIDE O P E N k Fig. 35—Checking Choke Unloader (wide o p e n kick) Adjustment c. Accelerator Pump Adjustment (1) Move t h e choke valve t o wide open position, t o release the fast idle cam. B a c k off t h e idle speed a d j u s t i n g screw ( c u r b i d l e ) u n t i l t h e t h r o t t l e valves are seated i n t h e bores. (2) Measure t h e distance f r o m t h e t o p o f t h e a i r h o r n t o t h e t o p o f t h e p l u n g e r shaft, u s i n g a " T " scale, as shown i n F i g u r e 36. T h i s distance should be 7/16 i n c h on A F B 29035. ( 1 ) W i t h t h e t h r o t t l e valves i n t h e wide open posit i o n , i t should be possible to i n s e r t Tool T109-31 ( % i n c h ) gauge between t h e upper edge o f t h e choke valve a n d t h e i n n e r w a l l o f t h e a i r h o r n , as s h o w n i n F i g u r e 35. (3) I f an adjustment is necessary, bend t h e t h r o t t l e connector r o d a t t h e l o w e r angle, u s i n g T o o l T109-213, u n t i l correct t r a v e l has been obtained. ( 2 ) I f a n a d j u s t m e n t is necessary, bend t h e u n loader l i p o n t h e t h r o t t l e shaft lever, u s i n g Tool T109-41, u n t i l correct opening has been obtained. (1) To check t h e secondary t h r o t t l e lever adjustment, block t h e choke valve i n t h e w i d e open p o s i t i o n and i n v e r t t h e carburetor. d. Secondary Throttle Lever Adjustment -SCALE PLUNGER S H A F T s HOKE VALVE OPEN *7/16 A1 THIS A N G J f : 11 : ; Ah- SHAHK O F FAST - IDLE ADJUSTING •V BEND THROTTLE C O N N E C T O R AT THIS A N G L E , V- Vv 34—Fast Idle C a m Indexing IDLE SPEED SCREW BACKED O F F THROTTLE VALVES SEATED IN BORES VALVfS CLOS Fig. INCH Fig. 58*292 36—Checking Accelerator Pump Travel FUEL SYSTEM —25 Fig. 39—Cross-Over Choke Control Unit Fig. 37—Checking Secondary Throttle Opening (2) Slowly open t h e p r i m a r y t h r o t t l e valves u n t i l i t is possible t o measure 19/64 i n c h between the lower edge of the p r i m a r y valve and the bore (opposite idle p o r t ) as shown i n F i g u r e 37. A t t h i s measurement, the secondary valves should j u s t s t a r t to open. (3) The stop lugs on b o t h t h e p r i m a r y and secondary t h r o t t l e levers should contact the bosses on the flange at the same t i m e . (4) I f an a d j u s t m e n t is necessary, bend the seco n d a r y t h r o t t l e o p e r a t i n g r o d at the angle, u s i n g Tool T109-213, u n t i l correct adjustment has been obtained. (5) A t wide open t h r o t t l e , the p r i m a r y and seco n d a r y t h r o t t l e valves should reach the f u l l v e r t i c a l position. ( 6 ) W i t h t h e p r i m a r y and secondary t h r o t t l e valves i n the t i g h t l y closed p o s i t i o n , i t should be possible t o I n s e r t Tool T109-29 (.020 i n c h ) w i r e gauge, between the positive closing shoes on the secondary t h r o t t l e levers, as shown i n F i g u r e 38. ( 7 ) I f a n a d j u s t m e n t is necessary, bend t h e shoe on the secondary t h r o t t l e lever, u s i n g T o o l T109-22, u n t i l correct clearance has been obtained. ©. Secondary Throttle Lock-Out Adjustment ( 1 ) Crack t h e t h r o t t l e valves, t h e n m a n u a l l y open and close the choke valve. T h e t a n g on the secondary t h r o t t l e lever should freely engage I n the notch o f the lock-out dog. ( 2 ) I f a n a d j u s t m e n t is necessary, bend t h e t a n g on the secondary t h r o t t l e lever, u n t i l engagement has been made. Use T o o l T109-22 f o r t h i s operation. (3) A f t e r adjustments have been made, r e i n s t a l l carburetor on engine, u s i n g a new gasket. (4) I t i s suggested t h a t t h e carburetor bowl be filled w i t h clean gasoline. T h i s w i l l help prevent d i r t t h a t is t r a p p e d i n the fuel system f r o m being dislodged b y the free flow o f fuel, as the carburetor is p r i m e d . 24. A U T O M A T I C CHOKE (Well Type) To f u n c t i o n p r o p e r l y , i t is i m p o r t a n t t h a t a l l p a r t s be clean and move freely. Other t h a n the occasional cleaning, the automatic choke c o n t r o l requires no servicing. I t is v e r y i m p o r t a n t , however, t h a t the choke c o n t r o l u n i t w o r k s freely at the t h e r m o s t a t i c coil s p r i n g h o u s i n g and at the choke shaft. Move the choke r o d up and d o w n to check f o r free movement of the coil h o u s i n g on the p i v o t . I f u n i t binds, a new u n i t should be installed. The W e l l T y p e Choke Cont r o l U n i t is serviced o n l y as a complete u n i t . D o n o t a t t e m p t to repair. (See F i g . 39.) Fig. 38—Checking Clearance Between Closing Shoes Do n o t l u b r i c a t e any p a r t s o f the choke o r c o n t r o l u n i t since t h i s causes d i r t accumulation w h i c h 26 — FUEL SYSTEM w o u l d result i n b i n d i n g of the choke mechanism. 25. IDLE SPEED ADJUSTMENT (Curb Idle) Do n o t a t t e m p t to change the c a l i b r a t i o n s e t t i n g . (Refer to specifications.) T h i s is pre-determined and should i t be changed, i m p r o p e r choke a c t i o n w o u l d result. The idle speed adjustment is made after the carbur e t o r has been installed on the engine. Clean a l l choke p a r t s u s i n g a suitable solvent and then b l o w d r y w i t h compressed a i r . E x a m i n e a l l choke p a r t s f o r wear or damage. W o r n or damaged p a r t s m u s t be replaced w i t h new i n order to i n s u r e p r o p e r choke operation. W h e n i n s t a l l i n g the w e l l t y p e choke u n i t , make c e r t a i n t h a t the coil h o u s i n g does n o t contact the sides o f the w a l l i n the i n t a k e m a n i f o l d . A n y contact at t h i s p o i n t w i l l affect choke operation. (1) W i t h t h e t h r o t t l e valves closed and t h e choke valve w i d e open (engine at n o r m a l o p e r a t i n g t e m p e r a t u r e ) , adjust the idle screw at 500 r p m (725750 r p m on A F B 2903S R a m M a n i f o l d C a r b u r e t o r s ) u s i n g a tachometer (550 r p m on a i r conditioner equipped c a r s ) . ( 2 ) A d j u s t t h e idle m i x t u r e screws u n t i l the engine operates smoothly, t h e n recheck the tachometer and again adjust the idle screw to give the correct engine r p m . F U E L TANK DATA AND SPECIFICATIONS FUEL TANK Location Conventional-Under T r u n k Compartment T o w n and Country—Left Rear Q u a r t e r Panel Capacity (Gallons) ( A l l De Soto, C h r y s l e r a n d I m p e r i a l Models except T o w n and C o u n t r y ) 23 T o w n a n d C o u n t r y Models 22 Filler Cap N o n Vented SPECIAL TOOLS C-3582-Spanner Wrench (Fuel Gauge) C - 3 5 8 4 - F i l l e r Tube Remover ( T o w n and C o u n t r y and I m p e r i a l ) FUEL SYSTEM —27 F U E L TANK The fuel t a n k on a l l models except the T o w n and The fuel t a n k on a l l models except the T o w n and C o u n t r y Models is located at the rear of the body, C o u n t r y has a 23 gallon capacity. under the t r u n k c o m p a r t m e n t C o u n t r y capacity is 22 gallons. F i g u r e 40. floor, as shown I n I n the T o w n and C o u n t r y models, the The T o w n and The filler tube on the conventional models is accessible t h r o u g h the fuel t a n k Is mounted i n the left r e a r q u a r t e r panel center o f the deck opening lower panel, w h i l e the beyond the wheel house, as shown i n F i g u r e 4 1 . T o w n and C o u n t r y fills at the left rear upper quar- appreciable t e r panel between the q u a r t e r post and the f i n . The l e n g t h of t i m e , the gasoline should be drained f r o m fuel t a n k is fitted w i t h a gauge u n i t , i n c l u d i n g the If the vehicle is to stored f o r any the entire system, I n order to prevent g u m f o r m a - suction pipe, as shown i n F i g u r e 42. The filter on t i o n . I f the vehicle has been undercoated, be sure the the end o f the suction pipe Is a replaceable u n i t and fuel t a n k vent tube (under k i c k u p i n floor pan) Is prevents the e n t r y of w a t e r or d i r t . W h e n i n s t a l l i n g open. I f t h i s is not done, a collapsed fuel t a n k w i l l a t a n k u n i t , be sure the filter is pushed on the end result. of the tube u n t i l seated. Fig. 40—Fuel Tank M o u n t i n g 28 —FUEL SYSTEM SERVICE PROCEDURES 26. FUEL TANK (Fig. 40) A L L DESOTO A N D CHRYSLER MODELS (Except Town and Country and Imperial) b. Installation a. Removal Before i n s t a l l i n g the t a n k gauge u n i t , check the condition of the filter on the end o f suction tube. I f filter is corroded, i n s t a l l a new filter. ( 1 ) D r a i n the tank, disconnect t h e fuel line and the w i r e lead to the gauge u n i t . (1) Position fuel t a n k gauge u n i t i n tank, using a new gasket. T i g h t e n securely, u s i n g Tool C-3582. ( 2 ) Disconnect vent tube a t hose connection at leading edge o f t a n k . ( 3 ) Remove the nuts t h a t hold t h e ends o f the fuel t a n k hold d o w n straps to the f r a m e . L o w e r f r o n t end of t a n k f a r enough to disengage filler tube f r o m r e a r panel and slide out f r o m under car. ( 4 ) Remove the t a n k gauge u n i t , using spanner w r e n c h Tool C-3582. Check the r u b b e r g r o m m e t a r o u n d the filler tube. I f cracked or deteriorated, i n s t a l l a new g r o m m e t at reassembly. ( 2 ) Slide the fuel t a n k under car. Raise t h e t a n k f a r enough to engage the filler spout w i t h the openi n g i n the r e a r panel. ( 3 ) Push t h e t a n k t o w a r d t h e rear t o f u l l y engage the filler spout i n the opening. ( 4 ) H o l d the fuel t a n k i n t h i s position, and place the hold d o w n straps i n position, feeding the attachi n g studs t h r o u g h holes i n the end of the straps. I n s t a l l the nuts b u t do not t i g h t e n . CAP ASSY TANK ASSY 60x97 Fig. 41 — F u e l Tank Mounting (Town a n d Country) FUEL SYSTEM —29 ( 3 ) U s i n g Tool C-3584, hooked i n t o t h e filler tube cap opening, p u l l the filler tube out of the fuel t a n k . A s filler tube is being removed, the vent tube on the filler tube w i l l p u l l out of the connector hose. (Refer t o F i g . 43.) Slide g r o m m e t off filler tube. - S U C T I O N TUBE FITTING -TERMINAL ( 4 ) Loosen t h e nuts t h a t hold t h e ends o f t h e fuel t a n k hold d o w n straps u n t i l the b u t t o n head studs can be disengaged f r o m the floor p a n brackets. D i s engage studs f r o m brackets and at the same t i m e s u p p o r t the t a n k . D r o p the t a n k s t r a i g h t d o w n and out f r o m under car. G A U G E UNIT S U C T I O N TUBE FILTER FLOAT57x275 Fig. 42—Fuel Gauge Tank Unit ( 5 ) Guide the b u t t o n head o f t h e studs i n t o t h e slots i n the f r a m e and d o w n i n t o p o s i t i o n . T i g h t e n the hold d o w n strap a t t a c h i n g nuts securely. ( 6 ) Slide t h e vent tube hose over t h e end o f the vent tube. Connect the lead w i r e to the t a n k gauge u n i t and reconnect the fuel line. ( 7 ) Refill the t a n k and check f o r leaks. 27* FUEL T A N I (Imperial) (Fig, 43) a. Removal ( 1 ) D r a i n t h e t a n k , t h e n disconnect t h e fuel line a n d the lead w i r e to the gauge u n i t . ( 2 ) Disengage t h e vent tube f r o m t h e vent tube hose. (Refer to F i g . 43.) ( 5 ) Remove t h e gauge t a n k u n i t , using spanner w r e n c h Tool C-3582. Check the r u b b e r g r o m m e t removed f r o m the filler tube. I f cracked or deteriorated, i n s t a l l a new g r o m m e t at reassembly. b. Installation Before i n s t a l l i n g the t a n k gauge u n i t , check the cond i t i o n of the filter on the end o f suction tube. I f filter is corroded, i n s t a l l a new filter. ( 1 ) Position the fuel t a n k gauge u n i t i n t a n k , u s i n g a new gasket. U s i n g Tool C-3582, t i g h t e n u n i t securely. (2) Place a new " 0 " seal r i n g i n the fuel t a n k filler neck. ( 3 ) Slide t h e fuel t a n k up i n t o position against floor pan. I n s t a l l the b u t t o n head studs i n t o slots i n the m o u n t i n g brackets. Snug nuts d o w n b u t do not tighten. Fig. 43—Fuel Tank Mounting (Imperial) 30 — FUEL SYSTEM ( 4 ) Slide g r o m m e t over t h e filler tube, t h e n i n s e r t filler tube t h r o u g h opening i n rear p a n e l (Be sure the vent tube Is up and engages the r u b b e r hose connection.) ( 5 ) Push the filler tube d o w n u n t i l the tube is aligned w i t h the t a n k neck opening. U s i n g a r u b ber hammer, d r i v e the tube i n t o the seal r i n g u n t i l the dimples on the tube seat on the shoulder o f the seal retainer. (Check to see t h a t the v e n t tube has entered the hose c o r r e c t l y . ) ( 6 ) Connect t h e vent tube on t h e f o r w a r d end o f the t a n k w i t h the r u b b e r hose and vent tube m o u n t e d on the floor pan. Be sure the end of the tube is open. (Refer to F i g . 43.) ( 7 ) T i g h t e n t h e t a n k hold down 'strap a t t a c h i n g nuts securely. Connect the fuel line to the t a n k and w i r e lead to the t a n k u n i t . ( 8 ) Refill the t a n k and check f o r leaks. disengage the hold d o w n strap f r o m the bracket. I f strap is to be replaced, refer to F i g u r e 4 1 . ( 7 ) Loosen t h e t a n k gauge u n i t , using a spanner w r e n c h Tool C-3582. Slide the u n i t up and out of the t a n k . Check the condition o f the rubber " 0 " r i n g . I f cracked or deteriorated, Install a new " 0 " r i n g at reassembly. b. Installation Before I n s t a l l i n g the t a n k gauge u n i t , check the cond i t i o n o f the filter on the end o f suction tube. I f the filter is corroded, i n s t a l l a new filter. ( 1 ) Position t h e fuel t a n k gauge u n i t I n t a n k , using a new gasket. T i g h t e n securely, u s i n g Tool C-3582. ( 2 ) Slide the hold down strap up under quarter panel, i n s e r t i n g the end o f strap i n t o slot. A l l o w the strap to hang. 28. FUEL T A N 1 (Town and Country) (PC-1, PC-3) (Fig. 41) ( 3 ) I n s t a l l a new " 0 " r i n g I n the neck o f t h e tank. (Fig. 41). a. Removal ( 4 ) Slide the t a n k up under t h e q u a r t e r panel w i t h the gauge u n i t f a c i n g f r o n t o f the vehicle. Push the t a n k up Into position. M a k e sure the filler neck is aligned w i t h the opening i n top o f the q u a r t e r panel. A t t a c h w i t h the strap and bolt. Do not tighten. ( 1 ) D r a i n t h e t a n k , and disconnect t h e fuel line and the lead to the gauge u n i t under the r e a r fender, behind the wheel house. ( 2 ) Remove t h e screws t h a t a t t a c h the stone shield t o the l o w e r edge o f the wheel house a t the rear. Remove the shield. ( 3 ) Remove t h e b u t t o n p l u g at the r e a r of wheel house ( i n f r o n t o f gauge u n i t ) . ( 4 ) Remove t h e bolt and washer t h a t attaches t h e t a n k hold d o w n s t r a p to the l o w e r support. ( 5 ) Place a new gasket over the filler tube and d o w n against the flange. I n s e r t the filler tube d o w n Into neck o f t a n k . D r i v e the tube Into " 0 " r i n g u n t i l the dimples I n the tube contact the seal r e t a i n er. Be sure the anchor tab on tube is aligned w i t h a screw hole. I n s t a l l the screws and t i g h t e n securely. ( 5 ) Remove t h e filler cap a n d t h e filler tube sleeve a t t a c h i n g screws. U s i n g a suitable tool, o r T o o l C-3584, p u l l out the filler tube. Slide the sleeve out of the body opening. Remove the gasket f r o m sleeve and " 0 " r i n g f r o m the filler tube. ( 6 ) T i g h t e n t h e fuel t a n k hold down strap bolt securely. ( 6 ) Slide the t a n k d o w n and o u t f r o m under the q u a r t e r panel. Reach up under the q u a r t e r panel and F o r t e s t i n g the fuel gauge, refer to the E l e c t r i c a l Group, "Gauges." ( 7 ) I n s t a l l t h e stone shield. Connect fuel line and lead to gauge u n i t . Reinstall the b u t t o n plugs. Refill the t a n k and check f o r leaks. FUEL SYSTEM —31 RAM INDUCTION MANIFOLD The R a m I n d u c t i o n M a n i f o l d equipped engine, as shown i n F i g u r e 44, consists o f t w i n a i r cleaners, t w i n A F B carburetors ( w i t h individual automatic w e l l t y p e chokes) a n d t w o a l u m i n u m m a n i f o l d s , cont a i n i n g e i g h t long sweeping passages ( f o u r i n each m a n i f o l d ) a l l o f w h i c h represent a n e w method o f fuel i n d u c t i o n . The a i r - f u e l m i x t u r e f r o m each c a r b u r e t o r flows i n t o a chamber d i r e c t l y under t h e c a r b u r e t o r , t h e n passes t h r o u g h t h e long i n d i v i d u a l i n t a k e branches to t h e opposite c y l i n d e r b a n k . T h e r i g h t h a n d carbur e t o r supplies a i r - f u e l m i x t u r e f o r t h e left h a n d cylinder bank, whereas t h e left h a n d c a r b u r e t o r MANIFOLD EQmuim TUBE HAM supplies the r i g h t hand c y l i n d e r bank. T h e passages between t h e r i g h t a n d left h a n d m a n i f o l d s are i n t e r connected w i t h a pressure equalizer tube, t o m a i n t a i n balance o f the engine pulsations. The t h r o t t l e l i n k a g e operates t h r o u g h a center m o u n t e d b a l l c r a n k a n d controls b o t h c a r b u r e t o r s a t t h e same t i m e . I t is v e r y i m p o r t a n t t h a t i f one o r more o f t h e c a r b u r e t o r s has been removed o r e i t h e r m a n i f o l d , t h a t a complete l i n k a g e a d j u s t m e n t be made i n o r d e r t o o b t a i n peak engine performance. (Refer t o P a r a g r a p h 3 1 o f t h i s G r o u p f o r s e t t i n g the t h r o t t l e l i n k a g e . ) AIR RESONATOu TUBES i — Fig. 44—Ram Manifold (Sectional V i e w ) 60^167 32 — FUEL SYSTEM SERVICE PROCEDURES 29. REMOVING THE R A M MANIFOLDS Should i t become necessary to remove e i t h e r the r i g h t or left i n t a k e ( o r b o t h ) m a n i f o l d s , refer to F i g ure 45, t h e n proceed as f o l l o w s : (1) D r a i n the cooling system. (2) Remove the c a r b u r e t o r a i r cleaners. ( 3 ) Disconnect t h e fuel line between the fuel p u m p and the left hand c a r b u r e t o r . (4) Disconnect the fuel line between the l e f t and r i g h t hand carburetor. ( 5 ) Disconnect the v a c u u m line between the r i g h t h a n d c a r b u r e t o r and the d i s t r i b u t o r . Disconnect the A n t i - S t a l l device v a c u u m line. (6) Remove the h i g h tension coil w i r e . ( 7 ) Disconnect the t h r o t t l e linkage at b o t h carburetors and the bellcrank, to the accelerator shaft. ( 8 ) Loosen the clamps t h a t attach the equalizer tube couplings to the manifolds and to the equalizer tube. Slide either coupling i n w a r d on the tube f a r enough to clear the m a n i f o l d tube opening. L i f t the equalizer tube, couplings and clamps up and a w a y f r o m engine. ( 9 ) Disconnect the power steering hoses ( i f so equipped) at the p u m p and secure against the fire wall. (10) Remove the a i r conditioning compressor and brackets ( i f so equipped). Refer to A i r C o n d i t i o n i n g , Group 24. To remove the left follows: Fig. 45—Ram Manifold (Exploded V i e w ) hand m a n i f o l d , proceed as FUEL SYSTEM —33 (11) Remove the e i g h t a t t a c h i n g bolts t h a t hold the left fender shield access plate to the fender shield, t h e n slide the plate o u t o f t h e engine compartment. (12) Remove t h e t w o bolts t h a t attach the left hand by-pass pipe t o t h e lower chamber. (13) Remove t h e t w o bolts t h a t a t t a c h t h e left hand exhaust m a n i f o l d elbow to the lower chamber. D i s c a r d t h e gaskets. (14) Remove t h e f o u r bolts t h a t attach t h e r a m m a n i f o l d t o t h e r i g h t bank cylinder head. Remove the exhaust passage crossover cover. (15) L i f t t h e r a m manifold and carburetor f r o m the engine as an assembly. -RIGHT BANK CARBURETOR ROD BELL CRANK ADJUSTING LINK 3/16"x3" PIN (WELDING ROD) (5) L O C K I N G BOLT AND NUT TOP VIEW ADJUSTING LINK (D L O C K I N G NUT © LOCKING BOLT A N D NUT ACCELERATOR SHAFT TO TRANSMISSION ROD TRANSMISSION THROTTLE CONTROL LEVER K I C K D O W N POSITION WIDE OPEN THROTTLE POSITION LEFT BANK CARBURETOR ROD L O C K I N G NUT 0 ANTI-STALL UNIT \ » D L E POSITION ACCELERATOR PEDAL T O SHAFT ROD BELL CRANK 3/16"xl0" PIN (WELDING ROD) ACCELERATOR SHAFT TO THROTTLESHAFT LEVER ROD ACCELERATOR SHAFT BRACKET ACCELERATOR PEDAL ACCELERATOR PEDAL T O SHAFT ROD ACCELERATOR SHAFT T O TRANSMISSION ROD SIDE VIEW ® LOCKING NUT' ADJUSTING LINK Fig. 46—Throttle Linkage - Ram Manifold (Schematic V i e w ) 60x191 34 —FUEL SYSTEM (16) Remove the nuts t h a t attach t h e carburetor to the i n t a k e m a n i f o l d , t h e n disconnect the a u t o m a t i c choke r o d f r o m the lever. Remove the c a r b u r e t o r . m a t i c choke control r o d w i t h the choke lever. Secure w i t h clip. I n s t a l l the carburetor m o u n t i n g nuts and t i g h t e n . (17) Remove the t w o bolts t h a t r e t a i n t h e autom a t i c choke I n the m a n i f o l d . L i f t choke assembly, gasket, reinforcement and w e l l cup out o f the m a n i fold. ( 3 ) Place the intake manifold assembly i n posit i o n on the r i g h t hand bank cylinder head. Place the exhaust crossover passage cover over the passage, t h e n i n s t a l l the m a n i f o l d a t t a c h i n g bolts finger tight. To remove the r i g h t h a n d r a m m a n i f o l d , proceed as follows : (18) Remove the eight a t t a c h i n g bolts t h a t hold the r i g h t fender shield access plate to the fender shield, t h e n slide the plate out o f the engine compartment. (19) Remove t h e t w o bolts t h a t a t t a c h t h e r i g h t hand exhaust bypass pipe to the l o w e r chamber. (20) Remove the t w o bolts t h a t a t t a c h the r i g h t hand exhaust m a n i f o l d elbow to the lower chamber. D i s c a r d the gaskets. (21) Remove the f o u r bolts t h a t a t t a c h the r a m m a n i f o l d to the left h a n d bank c y l i n d e r head. Remove the exhaust passage crossover cover. (22) L i f t t h e r a m manifold and c a r b u r e t o r f r o m the engine as an assembly. (23) Remove t h e nuts t h a t a t t a c h t h e carburetor to the i n t a k e m a n i f o l d , t h e n disconnect the autom a t i c choke r o d f r o m the lever. Remove the carburetor. (24) Remove the t w o bolts t h a t r e t a i n t h e autom a t i c choke i n the m a n i f o l d , l i f t choke assembly, gasket, r e i n f o r c e m e n t and w e l l cup out o f the m a n i fold. W i t h the manifolds removed, w o r k can n o w be done on c y l i n d e r heads, tappets, etc. 30. INSTALLING THE R A M M A N I F O L D W h e n i n s t a l l i n g the r a m m a n i f o l d , be sure and use new gaskets and be sure a l l m a t i n g surfaces are smooth a n d clean. Check to be sure t h a t b o t h m a n i fold heat c o n t r o l valves are o p e r a t i n g freely. I f stuck or b i n d i n g , free up, u s i n g heat c o n t r o l valve solvent. To i n s t a l l the left hand r a m i n t a k e m a n i f o l d , r e f e r to F i g u r e 45, t h e n proceed as f o l l o w s : ( 1 ) Place t h e automatic choke c o n t r o l u n i t i n t h e r e i n f o r c e m e n t and w e l l cup. Slide the assembly d o w n i n t o p o s i t i o n i n the i n t a k e m a n i f o l d , u s i n g a n e w gasket. I n s t a l l a t t a c h i n g bolts and t i g h t e n . ( 2 ) Place t h e c a r b u r e t o r i n position on t h e m o u n t i n g pad o f the i n t a k e m a n i f o l d and engage the auto- (4) Slide a new gasket between t h e left hand exhaust m a n i f o l d elbow and the lower chamber o f the i n t a k e m a n i f o l d . I n s t a l l a t t a c h i n g bolts finger t i g h t . ( 5 ) Slide a new gasket between t h e left hand exhaust by-pass pipe and the m a n i f o l d l o w e r chamber. I n s t a l l the a t t a c h i n g bolts and t i g h t e n to 10 footpounds torque. T i g h t e n the elbow a t t a c h i n g bolts to 10 foot-pounds torque and the i n t a k e m a n i f o l d bolts to 50 foot-pounds torque. (6) Slide the left hand fender shield access plate i n t o position against the fender shield. I n s t a l l the bolts and t i g h t e n . I f b o t h r a m manifolds were removed, continue to i n s t a l l the r i g h t hand m a n i f o l d as f o l l o w s : (7) Place the automatic choke control u n i t i n t h e reinforcement and w e l l cup, slide the assembly d o w n i n t o p o s i t i o n i n the intake m a n i f o l d , u s i n g a new gasket. I n s t a l l a t t a c h i n g bolts and t i g h t e n . ( 8 ) Place t h e c a r b u r e t o r i n position on the m o u n t i n g pad o f the i n t a k e m a n i f o l d and engage the autom a t i c choke c o n t r o l r o d w i t h the choke lever. Secure w i t h clip. I n s t a l l the c a r b u r e t o r m o u n t i n g nuts and tighten. (9) Place the intake m a n i f o l d assembly i n posit i o n on the left hand bank c y l i n d e r head. Place the exhaust crossover passage cover over the passage, then i n s t a l l the m a n i f o l d a t t a c h i n g bolts finger tight. (10) Slide a new gasket between t h e r i g h t h a n d exhaust m a n i f o l d elbow and the lower chamber of the i n t a k e m a n i f o l d . I n s t a l l the a t t a c h i n g bolts finger t i g h t . (11) Slide a new gasket between t h e r i g h t hand exhaust by-pass pipe and the lower chamber. I n s t a l l a t t a c h i n g bolts and t i g h t e n t o 10 foot-pounds torque. T i g h t e n t h e elbow a t t a c h i n g bolts t o 10 foot-pounds torque and the i n t a k e m a n i f o l d bolts to 50 footpounds torque. (12) Slide the r i g h t h a n d fender shield access plate i n t o p o s i t i o n against the fender shield. I n s t a l l bolts and t i g h t e n . FUEL SYSTEM — 35 (13) Place the a i r c o n d i t i o n i n g compressor and brackets i n p o s i t i o n ( i f so equipped) and I n s t a l l the a t t a c h i n g bolts. T i g h t e n securely. (Refer t o the A i r C o n d i t i o n i n g G r o u p 24 f o r method o f r e c h a r g i n g the system.) (14) Reconnect t h e Power Steering hoses t o the p u m p ( i f so equipped). (Refer to Power Steering Group 19 f o r method of bleeding a i r out o f the system.) (15) Slide t h e equalizer tube, clamps and couplings over the m a n i f o l d tubes. Slide either c o u p l i n g o u t w a r d f a r enough t o firmly engage the m a n i f o l d . T i g h t e n the clamps securely. (16) Reconnect t h e t h r o t t l e linkage at b o t h carburetors and bellcrank to accelerator shaft. (17) (18) Reconnect t h e v a c u u m line between t h e left hand c a r b u r e t o r and the d i s t r i b u t o r and the v a c u u m line to the A n t i - S t a l l device. (19) Reconnect t h e fuel line between t h e l e f t and r i g h t h a n d carburetor. fuel (21) Reinstall the r i g h t and left c a r b u r e t o r a i r cleaners. (22) To p o s i t i o n the accelerator shaft, refer to F i g u r e 46 t h e n proceed as f o l l o w s : ( 1 ) Loosen t h e a d j u s t i n g nuts " A " and " B " (accelerator shaft to t r a n s m i s s i o n r o d and accelerator shaft to t h r o t t l e shaft lever r o d ) . ( 2 ) I n s e r t a piece of 3/16 inch d r i l l rod, 10 inches l o n g i n t o the accelerator shaft bracket and t h r o u g h hole i n the lever. ( 3 ) Move t h e transmission t h r o t t l e control lever f o r w a r d u n t i l i t stops. T i g h t e n the locknut " A " securely. T h i s positions the accelerator shaft. b. Positioning the Accelerator Pedal To p o s i t i o n the accelerator pedal, proceed as f o l l o w s : (1) Reinstall the h i g h tension coil w i r e . (20) Reconnect t h e fuel line between the p u m p and the left h a n d carburetor. a. Positioning the Accelerator Shaft Refill t h e cooling system to required capacity. A f t e r the r a m m a n i f o l d s have been installed, i t is v e r y i m p o r t a n t t h a t the s e t t i n g the t h r o t t l e l i n k a g e be p e r f o r m e d i n o r d e r to o b t a i n peak engine performance. 31. SETTING THE R A M MANIFOLD THROTTLE LINEAGE S e t t i n g the t h r o t t l e l i n k a g e is a v e r y i m p o r t a n t step, i f i m p r o p e r l y set. V a r i o u s conditions affecting car performance can be encountered, such as loss o f performance, no w i d e open t h r o t t l e response, delayed s h i f t i n g o f the transmission, no k i c k d o w n , delayed upshifts, etc. S e t t i n g the t h r o t t l e linkage is divided i n t o f o u r p a r t s ; namely, p o s i t i o n i n g t h e accelerator shaft, p o s i t i o n i n g the accelerator pedal, s e t t i n g t h e bellc r a n k and s y n c h r o n i z i n g each carburetor and adj u s t i n g a n t i - s t a l l device. I t is v e r y i m p o r t a n t t h a t the t h r o t t l e linkage be set i n t h i s order. A t any t i m e the t h r o t t l e linkage is reset, t h e a n t i - s t a l l device m u s t be reset. Unsnap t h e accelerator pedal t o shaft r o d . ( 2 ) T u r n the threaded end o f the r o d either i n or out u n t i l a measurement o f 114 degrees is obtained between the floor o f the car and the flat face o f the accelerator pedal. N O T E : T h i s measurement can be made w i t h a protractor. (3) A f t e r correct measurement has been obtained, reconnect the r o d . Remove t h e d r i l l r o d f r o m the accelerator shaft bracket. c. Setting the Bellcrcmk To set t h e bellcrank, refer t o F i g u r e 46, t h e n p r o ceed as f o l l o w s : (1) Loosen locking nuts " C " and " D " ( l e f t and r i g h t bank carburetor r o d s ) . (2) Back off the a n t i - s t a l l a d j u s t i n g plunger f a r enough t o allow t h e bellcrank to be pivoted. N O T E : H o l d the a n t i - s t a l l control push r o d w h i l e a d j u s t i n g set screw t o prevent damage t o t h e diaphragm. (3) P i v o t the bellcrank u n t i l a % inch piece of d r i l l r o d 3 inches long can be inserted t h r o u g h t h e bellcrank hole and d o w n i n t o the l o c a t i n g hole i n the intake manifold. 6 (4) Inspect each c a r b u r e t o r t o be sure t h e choke valves are open, t h a t t h e fast idle cams are released, and t h a t the t h r o t t l e valves are i n the closed position. (5) T i g h t e n l o c k i n g nuts " C " and " D " securely. Remove t h e d r i l l r o d f r o m bellcrank. (6) Push r e a r w a r d on t h e accelerator shaft to t h r o t t l e shaft lever r o d a d j u s t i n g l i n k , u n t i l stop is f e l t . T i g h t e n the l o c k i n g n u t " B " securely. 36 — FUEL SYSTEM 32. ADJUSTING THE ANTI-STALL DEVICE (1) To readjust the a n t i - s t a l l device, i t is necessary t h a t t h e engine be at n o r m a l o p e r a t i n g t e m perature and t h a t t h e curb Idle speed be 725 to 750 r p m and constant w i t h the t r a n s m i s s i o n i n n e u t r a l ( N ) and t h e a i r c o n d i t i o n i n g compressor " O N " ( i f so equipped). (See P a r a g r a p h 33 " A d j u s t i n g t h e R a m M a n i f o l d A F B 2903S Series C a r b u r e t o r s " to o b t a i n t h i s Idle speed.) ( 3 ) W i t h the t r a n s m i s s i o n I n D r i v e ( D ) and the p a r k i n g b r a k e and the foot brakes applied, the a n t i - s t a l l plunger t o w a r d the b e l l c r a n k clearance o f .010" has been obtained. (Refer to 47.) with turn until Fig. 33. ADJUSTING THE 1 A M M A N I F O L D AFB' 2903S SERIES CARBURETOR T w i n 4 b a r r e l A F B 2903S series carburetors are used on the R a m I n d u c t i o n M a n i f o l d equipped cars. These c a r b u r e t o r s are f u n d a m e n t a l l y the same as A F B 4 b a r r e l carburetors used on other 1960 models. T h e service procedures f o r disassembly, cleaning, Inspection and reassembly f o l l o w the same sequence o f operations as covered f o r the other A F B carburetors. The f o l l o w i n g i n f o r m a t i o n covers Only the adjustments t h a t differ f r o m conventional mounted carburetors. t a i n i n g a good idle setting, since these carburetors are equipped w i t h a bypass a i r bleed f o r s e t t i n g the idle speed. The i g n i t i o n t i m i n g should be checked to make c e r t a i n i t is w i t h i n specifications, 5 ° B T C on the Chrysler Model C300F and 7 y ° on the De Soto R a m Charge A d v e n t u r e r engine as t h i s also affects idle q u a l i t y . I f the i g n i t i o n t i m i n g is not w i t h i n specifications, disconnect the vacuum advance line at the d i s t r i b u t o r as there is f u l l v a c u u m advance at idle and set the t i m i n g w i t h the engine idle speed below 600 r p m and t r a n s m i s s i o n i n n e u t r a l and a i r c o n d i t i o n i n g compressor " O F F " ( i f so equipped). I f , under these conditions, idle speed is s t i l l above 600 r p m , adjust b o t h carburetor idle bypass a i r bleed screws equally u n t i l desired idle speed is obtained. 2 Connect the vacuum advance line and w a r m engine up to n o r m a l o p e r a t i n g temperature. Disconnect each c a r b u r e t o r t h r o t t l e r o d at the bell c r a n k on the m a n i f o l d , then proceed as f o l l o w s : ( 1 ) T u r n all a d j u s t i n g screws ( m i x t u r e and bypass) i n finger t i g h t . ( 2 ) Open the by-pass idle a i r bleed screws full turn. one ( 3 ) Open each idle m i x t u r e screw % t u r n . ( 4 ) Connect a tachometer, t h e n s t a r t the engine. a. Idle Speed and Mixture Adjustment (On the Vehicle) Before the Idle speed and m i x t u r e adjustments are made, inspect t o be sure t h a t the t h r o t t l e l i n k a g e to b o t h c a r b u r e t o r s allows the r e t u r n to the idle posit i o n simultaneously. T h i s is v e r y I m p o r t a n t i n ob- ( 5 ) T u r n the m i x t u r e screws on t h e left carb u r e t o r y t u r n at a t i m e u n t i l the smoothest idle has been obtained. 8 ( 6 ) Repeat t h i s procedure on the r i g h t carburet o r , keeping the m i x t u r e screws w i t h i n % t u r n of each other. ( 7 ) W i t h t h e transmission i n N e u t r a l ( N ) , a i r conditioning compressor " O N " ( i f so equipped) and p a r k i n g brake applied, set the curb idle speed f r o m 725 t o 750 r p m by a d j u s t i n g the by-pass a i r bleed screws on each carburetor. Be sure to keep the bypass a i r bleed screw openings equal on b o t h carburetors. ( 8 ) Repeat steps 5, 6 and 7 u n t i l a smooth idle a t 725 to 750 r p m has been obtained. ( 9 ) Connect each carburetor t h r o t t l e r o d at t h e bellcrank. 60x190 Fig. 47—Anti-Stall Adjustment I f either carburetor has been removed f o r cleani n g o r r e p a i r , set the t h r o t t l e linkage as o u t l i n e d under the " R a m M a n i f o l d " P a r a g r a p h 3 1 . FUEL SYSTEM —37 b. Fast Idle Adjustment (On Vehicle) W h e n m a k i n g fast idle adjustment on the vehicle, each A F B c a r b u r e t o r should be adjusted i n d i v d u a l l y . To make the fast idle adjustment, proceed as f o l lows : ( 1 ) T h e engine should be at n o r m a l operating t e m p e r a t u r e and have a c u r b idle speed of 725 to 750 r p m w i t h t r a n s m i s s i o n i n ( N ) and a i r conditioni n g compressor " O N " ( i f so equipped). (2) T u r n a i r c o n d i t i o n i n g compressor " O F F " ( i f so equipped). (3) Remove each a i r cleaner. (4) Disconnect each t h r o t t l e r o d at t h e bellcrank on the i n t a k e m a n i f o l d . (5) Open t h e t h r o t t l e valves of t h e l e f t carburetor far enough t o allow p o s i t i o n i n g o f the fast idle cam to the fast idle index m a r k . The r i g h t carburetor should r e m a i n at the curb idle p o s i t i o n . (6) A d j u s t fast idle screw u n t i l a f a s t idle speed of 1375 to 1425 r p m is obtained on the Chrysler Model C-300F and 1475 to 1525 on the De Soto R a m Charge A d v e n t u r e r engine. ( 7 ) A f t e r the desired engine speed has been obtained, open the t h r o t t l e s l i g h t l y to a l l o w the fast idle cam t o r e t u r n to the open choke ( o r off fast idle) position. ( 8 ) Repeat steps 5, 6 and 7 i n s e t t i n g r i g h t carb u r e t o r fast idle speed as i t is v e r y i m p o r t a n t at the completion of t h i s step ( 8 ) , t h a t each c a r b u r e t o r has identical fast idle speeds. N O T E : There is no specification for engine rpm with both carburetors simultaneously set at the fast idle position. ( 9 ) Connect b o t h carburetor t h r o t t l e rods to the bell crank. c. Indexing the Choke Piston Before i n d e x i n g the choke p i s t o n , be sure the i g n i t i o n system and t i m i n g are at the r e q u i r e d specifications, t h a t the m a n i f o l d heat c o n t r o l valves are opera t i n g p r o p e r l y ( t h i s is v e r y i m p o r t a n t f o r n o r m a l w a r m - u p of the e n g i n e ) . A f t e r the above items have been inspected and corrected i f necessary, index the choke p i s t o n as f o l lows : (1) Remove t h e choke housing baffle plate. ( 2 ) Remove t h e t h r o t t l e r e t u r n s p r i n g , so t h a t the t h r o t t l e can be set at one q u a r t e r open. (3) Be sure t h e choke valve is wide open. ( 4 ) Slide a .026 inch w i r e i n t o the choke piston slot, so t h a t the hook on the end enters the slot i n the cylinder, as shown i n F i g u r e 47. ( T h i s gauge can be made b y b e n d i n g the .026 i n c h end o f w i r e gauge Tool T109-189 t o f o r m the shape, as shown i n F i g . 47.) (5) Push on the choke valve, counter-clockwise, t r a p p i n g the w i r e gauge between the p i s t o n and the c y l i n d e r slot (choke l i n k a g e h a n g i n g f r e e ) . ( 6 ) I t should now be possible t o insert a N o . 32 d r i l l between the choke valve and w a l l o f the a i r h o r n . I f an a d j u s t m e n t is necessary, bend the l i n k t h a t connects the choke shaft to the choke p i s t o n lever (at angle) u n t i l the correct clearance has been obtained. ( 7 ) Place t h e choke baffle plate i n position and i n s t a l l r e t a i n i n g screws. T i g h t e n securely. (8) Connect t h e t h r o t t l e r e t u r n s p r i n g .