Generac Power Systems GTH - 990, Owner'S Manual

Page: 8 / 16

6
3. When changing the oil filter, use the following instructions:
A. Locate filter (Figure 6).
B. Place a suitable container beneath the oil filter and turn the
filter counterclockwise to remove the filter.
C. Coat the gasket of a new filter with engine oil. Turn the new
filter clockwise until the gasket contacts the filter adapter,
then tighten an additional 3/4 turn .
Figure 5 — Oil Drain
Figure 6 — Oil Filter
4. Remove the oil fill cap and insert a clean funnel into the oil
fill opening. Fill the crankcase with the recommended oil until
the oil level is at the full point on the dipstick. Refer to the
Specifications chart. POUR SLOWLY.
5. When the crankcase is filled to the proper level, install and
tighten the oil fill cap. Start engine to fill oil filter, recheck/
correct oil level.
CLEANING INTAKE SCREEN AND COOLING FINS
Inspect and clean the intake screen and the following engine cool-
ing fins: cylinder, cylinder head, oil filter base and oil cooler after
each use or as needed. Blow or brush out any debris to help the
engine run cooler. Continued operation with a clogged cooling
system can cause severe overheating and possible engine dam-
age. Do not pressure wash to avoid shorting and corrosion in the
wiring harness, oil pressure switch, solenoid and starter motor
(Figure 7).
Figure 7 — Clean Intake Screen & Oil Cooler Fins
SERVICING THE AIR CLEANER
The equipment’s air cleaner system is one of the most important
items to maintain. The engine will not run properly and may be
damaged if it is run with a dirty air cleaner system.
Service or replace the paper air filter per the "Maintenance
Schedule" section. Service or replace the filter more often if the
engine is operated under dusty or dirty conditions. Clean the foam
pre-filter (if equipped) every 25 hours of operation, or sooner
under dusty or dirty conditions.
Use the following instructions to clean or replace the air cleaner
components. Locate the engine configuration (Figure 8 or
Figure 9) and follow the instructions.

Never run this equipment without the com-
plete air cleaner system installed on the
engine. This could result in premature wear
to the engine.
Option 1
To clean or replace foam pre-cleaner (if equipped):
• Remove air cleaner cover, then foam pre-filter.
• Wash pre-cleaner in soapy water. Squeeze pre-filter dry in clean
cloth (DO NOT TWIST).
• Clean air cleaner cover before re-installing it.
To service or replace paper air filter:
• Remove air cleaner cover; then remove foam pre-filter (if
equipped) and remove paper filter.
• If the filter is too dirty, replace it with a new one. Dispose of the
old filter properly.
• Clean air cleaner cover then slip pre-cleaner over filter (if
equipped).
• Next insert new paper filter into the base of the air cleaner.
Re-install air cleaner cover.
DRAIN
FILTER
INTAKE SCREEN
OIL
COOLER
FINS
Maintenance