Generac
®
Power Systems, Inc.
19
3. Check the spark plug gap using a wire feeler
gauge. Adjust the gap to 0.76 mm (0.030 inch) for
7 kW and 0.50 mm (0.020 inch) for 12/15 kW by
carefully bending the ground electrode (Figure
4.8).
Figure 4.8 – Setting the Spark Plug Gap
4.7
BATTERY MAINTENANCE
The battery should be inspected per the “Service
Schedule,” Section 4.13 (Page 22). The following pro-
cedure should be followed for inspection:
1. Inspect the battery posts and cables for tightness
and corrosion. Tighten and clean as necessary.
2. Check the battery fluid level of unsealed batteries
and, if necessary, fill with DISTILLED WATER
ONLY. DO NOT USE TAP WATER IN BATTERIES.
3. Have the state of charge and condition checked.
This should be done with an automotive-type bat-
tery hydrometer.
Do not dispose of the battery in a fire. The
battery is capable of exploding.
A battery presents a risk of electrical shock
and high short circuit current. The following
precautions are to be observed when working
on batteries:
• Remove the 5A and 15A fuses 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 dis-
connecting 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
thoroughly 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 your 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 5A and 15A fuses are removed from
the generator control panel, or sparking may
occur at the battery posts as you attach the
cables and cause an explosion.
4.8
ADJUSTING GH-410/GT-990 VALVE
CLEARANCE
After the first 50 hours of operation, you should
adjust the valve clearance in the engine.
Important:
If you feel uncomfortable about doing this
procedure or you don't have the proper tools, please
contact your Generac Authorized dealer for service
assistance. This is a very important step to insure
longest life for your engine.
To adjust valve clearance:
• Make sure the engine is at room temperature.
• 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
with a #2 or #3 phillips screwdriver.
!
!
!
DANGER
Section 4 — Maintenance
Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators
SET PLUG GAP AT 0.76 mm / 0.50 mm
(0.030 inch / 0.020 inch)
