8
OPM-138/B
STARTING HINTS
1. COLD WEATHER
A. Use the proper oil for the temperature expected.
B. Use fresh winter grade fuel. Winter grade gasoline is
blended to improve starting. Do not use summer grade
gasoline.
2. HOT WEATHER
A. Use the proper oil for the temperature expected.
B. Use only summer blended gasoline. Using gasoline left
over from winter may cause the unit to vapor lock.
STOPPING AND STORING
1. Move the key to the “OFF” position.
2. Turn off the fuel supply valve.
3. Before extended storage (over 30 days) certain
precautions must be taken to ensure the fuel doesn’t
deteriorate and clog the fuel system.
NOTE:
The use of a fuel additive, such as Sta-Bil or
equivalent will minimize the formation of gum deposits
during storage. The additive may be added to gasoline in
the engines fuel tank or to gasoline in a storage container.
A. Add the fuel stabilizer to the fuel in the tank and run
for 2 minutes
to circulate the stabilizer throughout the fuel system.
B. If you choose to remove the remaining fuel from the
fuel tank, it must be drained into an approved
container.
C. Start the engine and allow it to run until all the fuel in
the carburetor and the fuel lines has been used up and
the engine stops.
NOTE:
Running the engine to use up the fuel in the lines
and carburetor will still leave a small amount of fuel in
carburetor. It is best extended storage to treat the fuel
before draining.
D. While the engine is warm, drain the oil and refill with
fresh
oil.
E. Clean dirt and chaff from cylinder, cylinder head fins,
blower housing, screen, and muffler areas.
F. Store in a clean and dry area.
OPERATING SPEED
The engine-generator must be run at the correct speed
in order to produce the proper electrical voltage and
frequency.
CAUTION: EQUIPMENT DAMAGE
The output voltage should be checked to ensure the
generator is working properly prior to connecting a load to
the generator. Failure to do so could result in damage to
equipment plugged into the unit and possible injury to the
individual.
All engines have a tendency to slow down when a load
is applied. When the electrical load is connected to the
generator, the engine is more heavily loaded, and as a
result, the speed drops slightly. This slight decrease in
speed, together with the voltage drop within the generator
itself, results in a slightly lower voltage when the generator
is loaded to its full capacity than when running no load.
The slight variation in speed also affects the frequency
of the output current. This frequency variation has no
appreciable effect in the operation of motors, lights, and
most appliances. However, electronic equipment and clocks
will be affected if correct RPM is not maintained. See Load
vs. Output chart.
Although individual units and models vary slightly, the
normal voltage and frequency of the engine-generator
described in this manual are approximately as follows,
under varying loads:
LOAD vs. OUTPUT
Generator
Load
Speed
(RPM)
Frequency
(Hz)
Voltage
None
3690
61.5
125V
Half
3600
60.0
120V
Full
3510
58.5
115V
The speed of the engine was carefully adjusted at the
factory so that the generator produces the proper voltage
and frequency. For normal usage, the speed setting should
not be charged. If the generator is being run continuously
on a very light load, it is often advisable to lower the
operating speed slightly.
Reference “D” in the following image is the speed
adjustment for this engine.
CAUTION: EQUIPMENT DAMAGE
SPEED ADJUSTMENTS SHOULD ONLY BE MADE BY
A QUALIFIED SERVICE TECH. Whenever making any
speed adjustments, check the unit with a voltmeter and a
frequency meter or a tachometer and be sure the voltage
and speed are correct.
Lower voltage may damage both the generator and any
load connected to it. Running the engine at excessively
high speeds results in high voltage, which may significantly
shorten the life of appliances being used.
9
3110-00
60706-239
LOAD VS. OUTPUT
Generator
Load
Speed
(RPM)
Frequency
(Hz)
Voltage
None
3690
61.5
125V
Half
3600
60.0
120V
Full
3510
58.5
115V
The speed of the engine was carefully adjusted at the
factory so that the generator produces the proper volt-
age and frequency. For normal usage, the speed set-
ting should not be changed. If the generator is being
run continuously on a very light load, it is often advis-
able to lower the operating speed slightly. Reference
“D” below is the speed adjustment for this engine.
CAUTION: EQUIPMENT DAMAGE
SPEED ADJUSTMENTS SHOULD ONLY BE
MADE BY A QUALIFIED SERVICE TECH.
Whenever making any speed adjustments, check
the unit with a voltmeter and a frequency meter or
tachometer and be sure the voltage and speed are
correct.
Lower voltage may damage both the generator and
any load connected to it. Running the engine at
excessively high speeds results in high voltage, which
may signi
fi
cantly shorten the life of appliances being
used.
Output voltage should be checked periodically to
ensure continued proper operation of the generating
plant and appliances. It should be check at the recep-
tacles using a portable meter.
CONNECTING THE LOADS
APPLYING THE LOADS
Allow the engine to warm up for two or three minutes
before applying any load. This will allow the engine to
reach normal operating temperature and oil to circu-
late throughout the engine. A short warm-up time will
permit the engine to work more ef
fi
ciently when the
load is applied and will reduce the wear in the engine,
extending its life.
Receptacles have been provided to allow loads to
be connected to the generator. The loads should be
added one at a time. If a large motor is being started;
or multiple motors are being started, they should be
started individually and the largest should be started
fi
rst.
CAUTION: EQUIPMENT OVERLOAD
Keep the generator load within the generator and
receptacle nameplate rating. Overloading may cause
damage to the generator and/or the loads .
Most electric tools and appliances will have the volt-
age and amperage requirements on their individual
nameplates. When in doubt, consult the manufacturer
or a local electrician. The nameplate amperage rating
for electric motors can be misleading. See “Starting
Electric Motors” in Unit Capabilities (page 4).
These engine-generator sets are inherently self regu-
lating based on engine speed. The engine governor
will automatically adjust itself to the load. No harm
to the generator will result if it is operated with no
load connected. Proper utilization of the receptacles
located on the control panel is necessary to prevent
damage to either the receptacles or the generator.
The generator is a limited source of electrical power,
therefore, pay special attention to the receptacle
and generator ratings. The nameplate rating can be
obtained through a single receptacle as long as the
receptacle amperage rating is not exceeded.
D
