16 Generac®Power Systems, Inc.
4.5.4 INSPECT COOLING SYSTEM
• Inspect engine cooling system at least once each
month.
• Check hoses for damage, deterioration, leaks, etc.
Correct any discrepancies found.
• Check hose clamps for tightness.
4.5.5 CHECK ENGINE COOLANT LEVEL
See “Checking Fluid Levels” in Section 4.4.
4.5.6 PERFORM VISUAL INSPECTION
Complete a thorough visual inspection of the entire
engine-generator monthly. Look for obvious damage,
loose, missing or corroded nuts, bolts and other fas-
teners. Look for fuel, oil or coolant leaks.
4.5.7 INSPECT EXHAUST SYSTEM
Inspect the exhaust system at least once every three
months. Check all exhaust system pipes, mufflers,
clamps, etc. for condition, tightness, leaks, security,
damage.
4.5.8 CHECK FAN BELT
• Inspect fan belts every three months. Replace any
damaged, deteriorated, worn or otherwise defec-
tive belt.
• Check fan belt tension. Thumb pressure, exerted
midway between pulleys, should deflect about 3/8
to 3/4 inch. Adjust belt tension as required.
4.5.9 INSPECT ENGINE GOVERNOR
Visually inspect electronic governor.
DANGER: Do not attempt to adjust the gover-
nor. Only qualified service facilities should
adjust the governor. Excessively high operat-
ing speeds are dangerous and increase the
risk of personal injury. Low speeds impose a
heavy load on the engine when adequate
engine power is not available and may short-
en engine life. Correct rated frequency and
voltage are supplied only at the proper gov-
erned speed. Some connected electrical load
devices may be damaged by incorrect fre-
quency and/or voltage. Only qualified service
technicians should adjust the governed speed.
4.5.10 CHANGING ENGI NE OIL
Refer to maintenance performed by authorized serv-
ice facilities for engine oil and filter change frequen-
cies.
Drain the oil while the engine is still warm from run-
ning. This means warm up the engine, shut it down
and drain immediately as follows:
1. Remove OIL DRAIN HOSE from its retaining clip.
2. Loosen and remove OIL DRAIN HOSE CAP.
Drain oil completely into suitable container.
3. When all oil has drained, install and tighten OIL
DRAIN HOSE CAP, and re-install into its retaining
clip.
4. Turn OIL FILTER (Figure 4.2) counterclockwise
and remove. Dispose of old filter.

Figure 4.2 - Oil Filter

5. Apply light coating of new engine oil to seal of new
oil filter.Install FILTER and tighten by hand only.
DO NOT OVERTIGHTEN.
6. Remove OIL FILL CAP. Add recommended oil (see
SPECIFICATIONS). DO NOT FILL ABOVE THE
DIPSTICK “FULL” MARK. Crankcase oil capacity
is 4.0 U.S. quarts (3.8 liters).
After refilling the crankcase with oil, always
check oil level on dipstick. NEVER OPERATE
ENGINE WITH OIL BELOW THE DIPSTICK
“ADD” MARK.
7. Start engine and check for oil leaks.
4.5.11 CHANGING TH E ENGINE AIR CLEANER
To replace the engine air cleaner, (part number
059402), simply remove the air cleaner cover and
replace the air filter making sure it is positioned
properly before reattaching the cover (Figure 4.3).
!
OIL FILTER
!
DANGER
Section 4 — Maintenance
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators