Generac Power Systems OHVI GSH 220 Service Manual page 28

SeCTIoN 6: CYlINder HeAd ANd vAlveS
INTAKE
VALVE
EXHAUST
VALVE
Figure 6-12. Intake and Exhaust Valves
3
2
Figure 6-13. Head Bolt Tightening Sequence
JAM NUT
Figure 6-14. Install Rocker Arm and Pivot Ball Stud
1
Adjust valve clearance with the engine at room temperature.
The piston should be at top dead center (TDC) of its compres-
sion stroke (both valves closed). Adjust valve clearance as
follows:
. Loosen the rocker arm jam nut. Use an allen wrench to
2. When clearance is correct, hold the pivot ball stud with
4
ROCKER
ARM
0.076mm (0.003")
PIVOT
BALL
STUD
PUSH ROD
GUIDE PLATE
6-
Figure 6-15. Install Push Rods
AdjuSTING vAlve CleArANCe
turn the pivot ball stud while checking the clearance
between rocker arm and valve stem with a feeler gauge
(see Figure 6-6). Refer to "SPECIFICATIONS" in the back
of this manual for proper clearance.
the allen wrench and tighten the rocker arm jam nut to
the specified torque with a crow's foot. After tightening
the jam nut, recheck valve clearance to make sure it did
not change.
GAUGE
Figure 6-16. Adjusting Valve Clearance