Adjusting Gh-410/Gt-530/990/999 Valve Clearance - Generac Guardian Serie Manuel Du Propriétaire

• Where electrolyte contacts the eyes, flush thor-
oughly and immediately with water and seek medi-
cal 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
touching 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 7.5A 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.
4.7 ADJUSTING GH-410/GT-530/
990/999 VALVE CLEARANCE
After the first six (6) months of operation, check the valve clear-
ance in the engine, adjust if necessary.
Important: If feeling uncomfortable about doing this procedure
or the proper tools are not available, please contact the Dealer for
service assistance. This is a very important step to ensure 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 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.
26
Section 4 — Maintenance
Air-cooled Generators
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
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.
NOTE:
Rocker
Arm
Valve
Stem
NOTE: