Choke Pulloft Diaphragm Adjustments:The choke pull-
off
diaphragm Partially opens the choke Plate following
engine
startup.
This
helps
prevent flooding and pro-
vides for smoother engine operation as the set
is
warm-
ing up. Use the following procedure to adjust.
Fuel
Pump
An electric fuel pump is used
to
supply fuel to the car-
buretor.
If
the
pump malfunctions
or
insufficient fuel
delivery is suspected, use the following procedures
to
test the fuel pump.
1.
2.
3.
4.
5.
Disconnect the diaphragm hose from the rear side
of the intake manifold and apply
1
to 2 inches (25.4
to
50.8
mm) Hg vacuum
to
the diaphragm. Diaph-
ragm stem should pull in and remain in while
vacuum is applied.
Apply finger pressure lightlyagainstthe choke lever
to
take up the free play
in
the pulloff linkage (see
Figure
6-16).
Check linkage alignment (as viewed from the top) of
diaphragm stem, pulloff linkage, and choke linkage.
Correct alignment
as
required
to
obtain one-half
travel
at
choke lever.
Move the choke lever back and forth
to
check for
free movement. Verify that choke does not bind or
stick.
Remove vacuum supply and reconnect the diaph-
ragm hose
to
rear side of intake manifold.
DIAPHRAGC
HOSE
h
%
CHOKE
LINKAGE
LEVER
Do not subsfitute automotive type
@@@&I
electric fuel pumps for standard
Onan
supplied
electric fuel pumps. The output pres-
sure is much higher andcan cause carburetor flooding
or
fuel leakage, creating a fire hazard.
Fuel Pump Test: Test the fuel pump by checking the
pump outlet pressure as follows:
1.
Remove fuel line from carburetor inlet and install a
pressure gauge.
2.
Press start switch and hold it for several seconds,
until pressure reading is constant.
3. The pressure reading for a good pump should fall
within
3-1
12 to
5
psi
(1
7.2
to 34.4 kPa). The pressure
should stay constant or drop
off
very slowly.
If
pressure reading is below
3
112
psi (17.2 kPa),
replace fuel pump.
If
pressure reading is at zero, stop engine cranking
and check electrical connections. Press the Start
switch and recheck pressure reading.
There are no serviceable components in the fuel
pump. Replace complete fuel pump assembly
if
defective.
FSlW
FIGURE
6-16.
CHOKE
PULLOFF DIAPHRAGM
6-1
7
To Next Page
Loading...
Need help?
General
