16 Generac
®
Power Systems, Inc.
CHANGING ENGINE OIL
Refer to maintenance performed by authorized service
facilities for engine oil and filter change frequencies.
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 4.3) counterclockwise and
remove. Dispose of old filter.
Figure 4.3 - 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 DIP-
STICK “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.
CHANGING THE ENGINE AIR CLEANER
To replace the engine air cleaner, (part number 59402),
simply remove the air cleaner cover and replace the air
filter making sure it is positioned properly before reat-
taching the cover (Figure 4.4).
Figure 4.4 – Engine Air Cleaner
See the “Service Schedule,” Section 6, for air cleaner
maintenance.
SPARK PLUGS
Reset the spark plug gap or replace the spark plugs as
necessary. See Section 6.
1. Clean the area around the base of the spark plugs to
keep dirt and debris out of the engine. Clean by
scraping or washing using a wire brush and com-
mercial solvent. Do not blast the spark plugs to
clean.
2. Remove the spark plugs and check the condition.
Replace the spark plugs if worn or if reuse is ques-
tionable. See the “Service Schedule,” Section 6, for
recommended inspection.
3. Check the spark plug gap using a wire feeler gauge.
Adjust the gap to 0.5-0.6 mm (0.020-0.025 inch) by
carefully bending the ground electrode (Figure 4.5).
Figure 4.5 – Setting the Spark Plug Gap
COOLANT CHANGE
Every year, have Authorized Service Facility drain, flush
and refill the cooling system. See SPECIFICATIONS for
cooling system recommendations.
!
OIL FILTER
Section 4 — Maintenance
Guardian Liquid-cooled 15 kW, 20 kW and 25 kW Generators
SET PLUG GAP AT 0.5-0.6 mm
(0.020-0.025 inch)
