- Generac STANDBY GENERATOR OWNER'S MANUAL 1.6L 20/25/30 kW
MAINTENANCE PERFORMED BY 
SERVICE FACILITIES 
 Before working on the generator, ensure the fol-
lowing:
The AUTO/OFF/MANUAL switch is in the OFF 
position.
The 15A fuse has been removed from the con-
trol box.
The 120VAC supply to the battery charger is 
switched OFF.
EVERY THREE MONTHS
1. Check battery condition.
2.  Inspect and test fuel system.
3. Check transfer switch.
4. Inspect exhaust system.
5.  Check engine ignition system.
6. Check fan belts.
ONCE EVERY SIX MONTHS
1.  Test Engine Safety Devices (low oil pressure, low 
coolant level, high coolant temperature).
ONCE ANNUALLY
1.  Test engine governor; adjust or repair, if needed.
2. Clean, inspect generator.
3. Flush cooling system.
FIRST 30 OPERATING HOURS
1.  Change engine "break-in" oil and filter.
FIRST 100 OPERATING HOURS
1.  Change engine oil and oil filter. After initial 
change, service engine oil and filter at 100 operat-
ing hours or six months, whichever comes first.
2. Retorque cylinder head.
3.  Retorque intake and exhaust manifold.
EVERY 500 OPERATING HOURS
1. Service air cleaner.
2. Check starter.
3.  Check engine DC alternator.
EVERY 800 OPERATING HOURS
1. Retorque cylinder head.
2.  Retorque intake and exhaust manifold.
3. Check engine compression.
4. Check valve clearance.
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COOLING SYSTEM
Air intake and outlet openings in the generator com-
partment must be open and unobstructed for contin-
ued proper operation. This includes such obstruc-
tions as high grass, weeds, brush, leaves and snow.
Without sufficient cooling and ventilating air flow, the 
engine/generator quickly overheats, which causes it 
to shut down. (See the installation diagram.)
 The exhaust system parts from this product get 
extremely hot and remains hot after shutdown. 
High grass, weeds, brush, leaves, etc. must 
remain clear of the exhaust. Such materials may 
ignite and burn from the heat of the exhaust 
system.
OVERLOAD PROTECTION FOR ENGINE 
DC ELECTRICAL SYSTEM
Engine cranking, start up and running are controlled 
by a solid state Engine Controller circuit board. 
Battery voltage is delivered to that circuit board via 
a 15 amp fuse. These overcurrent protection devices 
will open if the circuit is overloaded.
 If a circuit breaker opens or a fuse element 
melts, find the cause of the overload before 
resetting the circuit breaker or replacing the 
fuse.
CHECKING FLUID LEVELS
CHECK ENGINE OIL
Check engine crankcase oil level (Figure 10.1) at least 
every 20 hours of operation, or prior to use.
Remove oil dipstick and wipe dry with a clean, lint-
free cloth.
Install oil dipstick, then remove again.
Oil should be between FULL and ADD marks.
If oil level is below the dipstick ADD mark, remove 
oil fill cap-. Add the recommended oil to bring oil 
level up to the FULL mark. DO NOT FILL ABOVE 
THE “FULL” MARK. See “Engine Oil Recommen-
dations” for recommended oils.
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10-1
Standby Generator Sets
Maintenance
Maint011 Rev. D 06/07










