Download SERVICE MANUAL

REASSEMBLY OF BASIC ENGINE
1. Reassembling piston, connecting rod, crankshaft and crankcase
1.1 Installing main bearing
Main bearing
upper
CAUTION
Do not apply oil to the bearing outer surface, as the oil
may cause bearing seizure.
(1) Press the upper main bearing into position by aligning
its lug to the lug groove on the crankcase.
Note: The oil hole of the main bearing is aligned with the
oil hole of the crankcase by installing the upper main
bearing in alignment with the lug groove.
(2) Apply a small amount of engine oil to each bearing.
Oil groove
Align with lug groove.
Installing main bearing upper
1.2 Installing thrust plate
Install the thrust plates to the crankcase outside face of
rearmost bearing and to the main bearing cap with their
grooves facing outward.
Thrust plate, upper
1.3 Installing tappet
Apply engine oil onto the periphery of tappets, insert them
into the tappet holes.
Thrust plate, lower
Thrust plate, lower
Installing thrust plate
1.4 Installing crankshaft
(1) Install the wood ruff key on the crankshaft.
(2) Make sure that the main bearing upper shells that are
installed in the crankcase bores have their inner
periphery (the surface comes into contact with the
journal) lubricated with an even coat of fresh engine
oil.
(3) Wash the crankshaft thoroughly with cleaning oil and
dry it completely by blowing compressed air. Then,
apply an even coat of fresh engine oil to the crankshaft
journals.
Note: When cleaning the crankshaft, pay special attention to
the oil holes in the crank journals and crankpins, and
make sure that they are free from any foreign matter.
(4) Sling up the crankshaft horizontally, then move it above
the crankcase and lower it slowly into position.
Note: When lifting the crankshaft with a chain block, do not
attach a metal hook or similar fitting directly onto the
crankshaft. Such metal fittings can damage the
crankshaft easily. Always lift the crankshaft using
cloth belts or pads on the supporting points.
7-2
Installing crankshaft