Disconnect all loads from the generator set An accurate
frequency meter should be connected to the generator
output receptacle. Adjustments should be made
in
the
following sequence. To adjust the engine speed only,
proceed to steD
4.
Models
Wifh
1dlemafic:Set
the
Idlematic contml to
On. Adjust the high speed screw by turning
it
clockwise to increase engine speed
or
counter-
clockwise to decrease engine speed. One
full
turn
of
the adjustment screw
will
change the frequency
1.
2.
3.
4.
5.
Check the governor linkage for binding or exces-
sive looseness. Check the springs for bending
or
damage and straighten
or
replace as needed. Make
sure the spring(s) areattached tothecorrect mounting hole (Figure
6-1
0).
Loosen the screw at the lower end of the governor
lever [Figure
6-1
0).
Hold the throttle valve in the full yopen position with
the governor lever. Turn the groove on the governor
lever shaft fully clockwise with a screwdriver and
tighten in that position. Tighten the governor lever
tighteningscrew to5.1 to8.7ftlbs(6.9 to
11.8N.m).
Check to make sure throttle is held in the fuliy open
position after tightening.
Start the engine. Make sure the speed control lever
is in the high speed position or that the Idlematic is
Off
on’Pro models with. Idlematic. Operate the
generator set with no-load until it is warm. Refer to
Figure
6-10.
Check the no-load frequency for a normal reading
of
63.5
f0.5
Hz
(3780
-
3840
rpm)
or
53.5
k
0.5
Hz
(31 80
-
3240 rpm) for
50
Hz
models.
6.
If
an abnormal reading is measured, adjust the
speed as follows:
Models
Without
Idlemafk
Move the speed control
lever to a position between the high and low speed
settings. Adjust the high speed screw by turning it
counterclockwise to increase engine speed or
clockwise to decrease engine speed.
Models Below
5
kW.
One full turn of the adjustment
screw will change the frequency approximately
1
-
1
/4
Hertz.
Do
not turn the adjustment screw more
than 2 turns.
5
kW Models: One full turn of the adjustment screw
will change the frequency approximately
4
Hertz.
Do
not turn the adjustment screw more than
1/2
turn.
After making an initial adjustment, move the speed
control
lever to the high speed setting and recheck
frequency. Repeat this process until a normal no-
load speed
is
obtained.
approximately 3.7 Hertz.
Do
not turn the adjustment
screw more than
314
turns. After making an initial
adjustment, set the Idlematic control to
Off
and
recheck frequency. Repeat this process until
a
normal no-load speed is obtained.
Springs tend to lose their calibrated tension through
fatigue after long usage and may require replace-
ment If the governor action
is
erratic after adjustments are made, replace the spring. If this does not
improve operation, the problem may be within the
governor mechanism (see engine Block Assembly,
section
9).
FUEL
SYSTEM
The main components of the fuel system are the carburetor, air filter assembly, and fuel filter. Each of the
components in the fuel system must be in good working
condition and the carburetor must be properly adjusted
for efficient generator set operation. Referto thefollow-
ing sections for servicing each of these components.
See Figure
6-1
1.
Air Filter Assembly
Service the air filter at the intervals recommended in the
Operator’s Manual. In dusty conditions, service the air
filter more often. When replacing the air filter, use only
an Onan-approved filter. There are three types of air
filter assemblies used on these models: foam filter only,
foam wrapper on paper element, and paper element
only. Follow the filter service procedures that apply to
the filter system on the generator set
1.
Carefully remove the air cleaner cover and remove
the air cleaner element
2.
Follow the service procedures listed by the type of
filter used.
Foam
Wrapper
On
Paper Filter: Remove foam
wrapper and wash
in
detergentand water.
Dry
foam
wrapper thoroughly. Use low pressure air on the
inside of the paper element to remove dust and dirt.
Replace paper element at every sixth cleaning or
sooner if dusty operating conditions exist
PaperFi/ferOn/y:Use low pressureair on the inside
of the paper element to remove dust and dirt.
Replace paper element at every sixth cleaning or
sooner if dusty operating conditions exist.
3.
Reassemble filter into the housing and carefully
install the air cleaner cover.
6-1
1