Adjusting; Valve Clearance; Adjusting Gh-410/Gt-530/990 Valve Clearance - Generac Power Systems 7kW Installation And Owner's Manual

• Remove the 15A fuse from the generator control
panel.
• Remove watches, rings or other metal objects;
• Use tools with insulated handles;
• Wear rubber gloves and boots;
• Do not lay tools or metal parts on top of the
battery; and
• Disconnect charging source prior to connecting or
disconnecting battery terminals.

Do not open or mutilate the battery. Released
electrolyte has been known to be harmful to the
skin and eyes, and to be toxic.

The electrolyte is a dilute sulfuric acid that is
harmful to the skin and eyes. It is electrically
conductive and corrosive. The following
procedures are to be observed:
• Wear full eye protection and protective clothing;
• Where electrolyte contacts the skin, wash it off
immediately with water;
• Where electrolyte contacts the eyes, flush thor-
oughly and immediately with water and seek
medical attention; and
• Spilled electrolyte is to be washed down with an
acid neutralizing agent. A common practice is to
use a solution of 1 pound (500 grams) bicarbonate
of soda to 1 gallon (4 liters) of water. The bicar-
bonate of soda solution is to be added until the
evidence of reaction (foaming) has ceased. The
resulting liquid is to be flushed with water and the
area dried.

Lead-acid batteries present a risk of fire because
they generate hydrogen gas. The
following procedures are to be followed:
• DO NOT SMOKE when near the battery;
• DO NOT cause flame or spark in battery area; and
• Discharge static electricity from body before touch-
ing the battery by first touching a grounded metal
surface.

Be sure the AUTO/OFF/MANUAL switch is set to
the OFF position before connecting the battery
cables. If the switch is set to AUTO or MANUAL,
the generator can crank and start as soon as the
battery cables are connected.

Be sure the utility power supply is turned off
and the 15A fuse is removed from the generator
control panel, or sparking may occur at the bat-
tery posts as the cables are attached and cause
an explosion.
22
Section 4 — Maintenance
Air-cooled Generators
4.7 ADJUSTING GH-410/GT-530/990

VALVE CLEARANCE

After the first six (6) months of operation, check
the valve clearance in the engine, adjust if neces-
sary.
Important: If feeling uncomfortable about doing
this procedure or the proper tools are not available,
please contact the Authorized Dealer for service
assistance. This is a very important step to insure
longest life for the engine.
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 compression 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 direc-
tion. 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 (Figure 4.10).
To adjust valve clearance (if necessary):
• 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.
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.
NOTE:
NOTE: