Cylinder head assembly (continued), Installation – Generac 86640 User Manual
Page 37
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Cylinder Head Assembly (Continued)
6. Install oil pump Idler gear and oil pump regulator spring.
Make sure the spring faces in the proper direction.
Figure 41.
Oil pump spring stopper
Oil pump regulator spring ^
dJ
Oil pump drive gear
Installation
1. Set No. 1 cylinder head at top dead center (TDC) of its
compression stroke by first aligning the CAMSHAFTTIMING
PULLEY MARK with mark on the main bearing cap.
CAUTION: DO NOT rotate crankshaft and cam
shaft separately or valves will hit the piston heads.
2. Install cylinder head with a new gasket. The following rules
apply:
D Always use a new cylinder head gasket.
D Before tightening the cylinder head bolts, check that the
oil pump drive gear can be turned freely by hand.
D Always installwashers between bolts and head.
D Tighten cylinder head bolts in the sequence shown in
Figure 43.
3. Tighten cylinder head bolts as follows:
a. First, tighten all bolts to 22 foot-pounds (29 N-m).
b. Then, tighten all bolts to 47 foot-pounds (64 N-m).
c. Loosen all bolts completely.
d. Tighten all bolts to 22 foot-pounds (29 N-m).
e. Tighten all bolts to 47-51 foot-pounds (64-69 N-m).
NOTE: When RETORQUING cylinder head bolts for nor
mal periodic maintenance, first loosen all bolts slightly.
Then (with engine COLD), tighten all bolts In correct
sequence to 47-51 foot-pounds (64-69 N-m).
4. Install timing belt. Install oil pump Idler and oil pump
regulator spring (make sure spring direction is correct). Install
upper dust cover, making sure its gasket mates with cylinder
head properly.
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