Cooling System - Generac Power Systems 8 kW Owner's Manual

To check valve clearance:
• The engine should be cool before checking. If valve clearance is
0.002" - 0.004" (0.05 - 0.1mm), adjustment is not needed.
• Remove spark plug wires and position wires away from plugs.
• Remove spark plugs.
• Make sure the piston is at Top Dead Center (TDC) of its com-
pression stroke (both valves closed). To get the piston at TDC,
remove the intake screen at the front of the engine to gain
access to the flywheel nut. Use a large socket and socket
wrench to rotate the nut and hence the engine in a clockwise
direction. While watching the piston through the spark plug
hole. The piston should move up and down. The piston is at
TDC when it is at its highest point of travel.
To adjust valve clearance (if necessary), (Figure 4.9):
• Make sure the engine is at 60° to 80° F.
• Make sure that the spark plug wire is removed from the spark
plug and out of the way.
• Remove the four screws attaching the valve cover.
• Loosen the rocker jam nut. Use an 10mm allen wrench to turn
the pivot ball stud while checking clearance between the rocker
arm and the valve stem with a feeler gauge. Correct clearance
is 0.002-0.004 inch (0.05-0.1 mm).
Hold the rocker arm jam nut in place as the pivot ball
stud is turned.
When valve clearance is correct, hold the pivot ball stud in place
with the allen wrench and tighten the rocker arm jam nut. Tighten
the jam nut to 174 in/lbs. torque. After tightening the jam nut,
recheck valve clearance to make sure it did not change.
• Install new valve cover gasket.
• Re-attach the valve cover.
Figure 4.9 - Valve Clearance Adjustment
Pivot Ball
Stud
Jam Nut
26
Section 4 — Maintenance
Air-cooled Generators
NOTE:
Rocker
Arm
Valve
Stem
Start all four screws before tightening or it will not be
possible to get all the screws in place. Make sure the
valve cover gasket is in place.
• Install spark plugs.
• Re-attach the spark plug wire to the spark plug.
• On the GT-530 and GT-990/999, repeat the process for the
other cylinder.
4.8

COOLING SYSTEM

Air inlet and outlet openings in the generator compartment must
be open and unobstructed for continued proper operation. This
includes such obstructions as high grass, weeds, brush, leaves
and snow.
Without sufficient cooling and ventilating air flow, the engine/gen-
erator quickly overheats, which causes it to quickly shut down.
(See Figure 4.10 for vent locations.)
Make sure the doors and roof are in place during operation as
running the generator with them removed can effect cooling air
movement.
 The exhaust from this product gets extremely
hot and remains hot after shutdown. High grass,
weeds, brush, leaves, etc. must remain clear of
the exhaust. Such materials may ignite and burn
from the heat of the exhaust system.
Figure 4.10 – Cooling Vent Locations

The maximum ambient temperature for the gen-
erator is 25° C (77° F).
NOTE: