GMC 1976 ZEO 6083 Maintenance Manual page 701

24C- 24 ONAN MOTOR GENERATOR
Figure 34-Carburetor Float Adjustment
6. Install new gaskets when reassembling .
FUEL PUMP FILTER ELEMENT
(FIGURE 35)
Every 400 hours or sooner, drain fuel pump and
check filter element. Remove fuel pump mounting
screws and turn off hex nut on base of pump . If
element appears dirty, replace with a new one. Be
sure to replace gaskets when reassembling .
Figure 35-Fuel Pump Filter Element
FUEL SOLENOID
An electric fuel solenoid is mounted on the inlet
side of the fuel pump . The solenoid valve is closed
when the motor generator is not running, preventing
fuel from siphoning out of the pump and back to the
tank . The solenoid valve opens during cranking and
running. A defective solenoid will not allow the mo-
tor generator to start.
AIR CLEANER ELEMENT
(FIGURE 36)
Check and clean element at least every 100 hours.
Loosen wing nut to remove . Clean by tapping base
lightly on a flat surface. Replace element at least
every 200 operating hours on the 4KW and every
500 hours on the 6KW; clean or replace more often
in dusty conditions .
CARBURETOR ADJUSTMENTS
(FIGURE 37)
The carburetor has a main fuel (power) adjust-
ment and an idle fuel adjustment . The main adjust-
ment affects operation under heavy load conditions .
The idle adjustment affects operation under light or
no-load conditions . Under normal circumstances,
adjustments should not be disturbed. If adjustments
have been disturbed turn main fuel jet 1-1/4 turn off
its seat and idle fuel jet one turn off its seat to permit
starting . Then readjust them for smooth operation.
CAUTION:
Forcing the needle against its
seat will damage it. The needle does not
completely shut off 4rel when turned
fully
in . ?-
Set the throttle stop sdiew (located on the carbu-
retor throttle lever), with no load connected to the
plant. Turn stop so it just touches adjustment screw;
then turn adjustment screw (with stop still touching
it) until unit is running at 1500 rpm. When stop is
released, governor will then control no-load speed at
1850 to 1890 rpm.
Before final adjustment, allow the engine to
warm up . Adjust the idle fuel jet with no load con-
nected . Open the main jet unitl the engine runs
smooth under acceleration with no load . Slightly
more fuel may be needed (open about 1/4 turn fur-
ther) when sudden load is applied or if operating in
extremely cold weather.