Section 4 — Maintenance
Centurion
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
4.Turn OIL FILTER (Figure 4.2) counterclockwise and remove. Dispose of old 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).
7.Start engine and check for oil leaks.
Figure 4.2 - Oil Filter
See “Scheduled Maintenance”, Section 4.7, for air cleaner maintenance.
4.5.11 SPARK PLUGS
Reset the spark plug gap or replace the spark plugs as necessary. See Section 4.7.
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 commercial 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 questionable. See “Scheduled Maintenance”, Section 4.7, for recommended inspection.
3.Check the spark plug gap using a wire feeler gauge. Adjust the gap to
OIL FILTER
After refilling the crankcase with oil, always
!check oil level on dipstick. NEVER OPERATE ENGINE WITH OIL BELOW THE DIPSTICK “ADD” MARK.
4.5.10 CHANGING THE ENGINE AIR CLEANER
To replace the engine air cleaner, (part number 059402), remove the air cleaner cover and remove air cleaner. Clean bottom plate and install the air filter making sure it is positioned properly before reattaching the cover (Figure 4.3).
Figure 4.3 – Engine Air Cleaner
Air Cleaner
(Doors Removed for Clarity)
Figure 4.4 – Setting the Spark Plug Gap
SET PLUG GAP AT 
4.5.12 COOLANT CHANGE
Every year, have Authorized Service Facility drain, flush and refill the cooling system. See Section 1.10, SPECIFICATIONS, for cooling system recommen- dations.
4.6MISCELLANEOUS MAINTENANCE
4.6.1 CLEANING THE GENERATOR
Keep the generator as clean and as dry as possible. Dirt and moisture that accumulates on internal generator windings have an adverse effect on insulation resistance.
Periodically clean generator exterior surfaces. A soft brush may be used to loosen caked on dirt. Use a vacuum system or dry, low pressure air to remove any accumulations of dirt. The generator is housed inside an
Generac® Power Systems, Inc. 17
