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Page 58
TEST 33 – CHECK CARBURETION
DISCUSSION:
If the engine cranks but will not start, one possible
cause of the problem might be the carburetion system.
PROCEDURE:
Before making a carburetion check, be sure the fuel sup-
ply tank has an ample supply of fresh, clean gasoline.
Check that all shutoff valves are open and fuel flows
freely through the fuel line.
Make sure the automatic choke operates properly.
If the engine will not start, remove and inspect the spark
plug. If the spark plug is wet, look for the following:
❏Overchoking.
❏Excessively rich fuel mixture.
❏Water in fuel.
❏Intake valve stuck open.
❏ Needle/float stuck open.
If the spark plug is dry look for the following:
❏ Leaking carburetor mounting gaskets.
❏ Intake valve stuck closed.
❏ Inoperative fuel pump.
❏ Plugged fuel filter(s).
❏ Varnished carburetor
If the engine starts hard or will not start, look for the
following:
❏Physical damage to the AC generator. Check the
Rotor for contact with the Stator.
❏Starting under load. Make sure all loads are discon-
nected or turned off before attempting to crank and
start the engine.
❏Check that the automatic choke is working properly.
RESULTS:
If problem has not been solved, go to Test 34. If car-
buretor is varnished, clean or replace.
1. Remove fuel line at carburetor and ensure that
there is an adequate amount of fuel entering the
carburetor.
2. Remove the float bowl and check to see if there is
any foreign matter in bottom of carburetor bowl.
3. The float is plastic and can be removed for access
to the needle so it can be cleaned.
4. With all of this removed carburetor cleaner can
be used to clean the rest of the carburetor before
reassembly.
5. After cleaning carburetor with an approved carbu-
retor cleaner, blow dry with compressed air and
reassemble.
Shelf life on gasoline is 30 days. Proper procedures
need to be taken for carburetors so that the fuel doesn’t
varnish over time. A fuel stabilizer must be used at all
times in order to ensure that the fuel is fresh at all times.
TEST 34 – CHECK CHOKE SOLENOID
DISCUSSION:
The automatic choke is active only during cranking.
When the Start-Stop Switch is held at “START”, a
crank relay on the Printed Circuit Board is energized
closed to (a) crank the engine and (b) deliver a cyclic
voltage to the Choke Solenoid via Wire 14. The Choke
Solenoid will be pulled in for about two seconds, then
deactivate for about two seconds. This cyclic choking
action will continue as long as the engine is being
cranked.
PROCEDURE:
1. Operational Check: Crank the engine. While
cranking, the choke solenoid should pull in about
every 2 seconds (2 seconds ON, 2 seconds OFF).
If the choke solenoid does not pull in, try adjusting
the choke as follows.
2. Pre-Choke Adjustment: With the CHOKE
SOLENOID not actuated, the carburetor CHOKE
PLATE should be approximately 1/8 Inch from its
full open position. Verify choke is completely open
once engine is warmed up. If not, power will be
down and emissions will be up. Adjust position
of BI-METAL HEATER ASSEMBLY by loosening
screws until unit starts when cold and the choke
closes when engine is up to temperature. Tighten
the screws to complete the adjustment.
CHOKE
SOLENOID
BI-METAL
HEATER
SCREWS
STEPPER
MOTOR
Figure 7-41. – Automatic Choke Assembly
3. Choke Solenoid Adjustment: Loosen the screws
that retain the CHOKE SOLENOID to its brack-
et. Slide the CHOKE SOLENOID in the slotted
holes of the bracket to adjust axial movement of
the SOLENOID PLUNGER. Adjust SOLENOID
PLUNGER movement until, with the carburetor
CHOKE PLATE 0.5mm from closed, the CHOKE
SOLENOID is bottomed in its coil (plunger at
full actuated position). With the CHOKE PLATE
0.5mm from closed and the plunger bottomed
Section 7
DIAGNOSTIC TESTS