wsm wg972-e4, Workshop Manual

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ENGINE
WG972-E4, WSM
1-M2
[3] CYLINDER HEAD
Intake and Exhaust Port
The cross-flow type intake / exhaust ports, which
lower the heat conduction from the exhaust port to the
intake port. The low heat conduction keeps the intake air
from being heated and expanded by the exhaust gas.
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Combustion System
The Spark Ignition type combustion chamber,
compactly set on top of the piston head, successfully
reduces emissions. To ensure even more reliable
emission life, the intake / exhaust valve seats are fitted
with special heat resistant stellite alloys.
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[4] CRANKSHAFT
The crankshaft with the connecting rod converts the
reciprocating motion of the piston into rotating motion.
The crankshaft (2) has oil passages drilled so that oil can
flow from the main bearings to the crank pin bearings.
The front journal is supported by a sleeve type
bearing (crankshaft bearing 1) (1), the intermediate
journal by a split type (crankshaft bearing 3) (4), and the
rear by a split type (crankshaft bearing 2) (6) with thrust
bearings (5).
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(1) Intake Port (2) Exhaust Port
(1) Valve
(2) Valve Seat
(3) Main Combustion Chamber (4) Piston
(5) Spark Plug
(1) Crankshaft Bearing 1
(2) Crankshaft
(3) Feather Key (4) Crankshaft Bearing 3
(5) Thrust Bearing
(6) Crankshaft Bearing 2
KiSC issued 07, 2015 A