Check Carburetion; Check Choke Solenoid - Guardian 4700 Repair Manual

Section 7
DIAGNOSTIC TESTS
2. When clearance is correct, hold the pivot ball stud with the
allen wrench and tighten the rocker arm jam nut to the speci-
fied torque with a crow's foot. After tightening the jam nut,
recheck valve clearance to make sure it did not change.
TORQUE SPECIFICATION
ROCKER ARM JAM NUT
72 inch-pounds
INSTALL ROCKER ARM COVER
1. Use a new rocker arm cover gasket. Install the rocker arm
cover and retain with four screws.
2. Install oil breather tube
RESULTS:
Adjust valves to specification and retest.
TEST 36 - CHECK CARBURETION
DISCUSSION:
If the engine cranks but will not start, one possible
cause of the problem might be the carburetion sys-
tem.
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.
Page 48
RESULTS:
If problem has not been solved, go to Test 37. If car-
buretor is varnished, clean or replace.
1. Remove fuel line at carburetor and ensure that there is an ade-
quate 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 bow..
3. The float is plastic and can be removed for access to the nee-
dle so it can be cleaned.
4. With all this removed you can use carburetor cleaner to clean
the rest of the carburetor before reassembly.
5. After cleaning carburetor with an approved carburetor 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. You must use a fuel stabilizer at all
times in order to ensure that the fuel is fresh at all times.
TEST 37 - 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 Engine Controller circuit board is
energized closed to (a) crank the engine and (b)
deliver a cyclic voltage to the Choke Solenoid via
Wire No. 90. 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 sec-
onds ON, 2 seconds OFF). If the choke solenoid does not pull
in, try adjusting the choke as follows.
2. Pre-Choke Adjustment: With the SOLENOID CHOKE not actu-
ated, the carburetor CHOKE PLATE should be approximately
1/8 Inch from its full open position. If necessary, use needle
nose pliers to bend the tip of the BI-METAL CHOKE HEATER
until the desired setting is obtained.
3. Choke Solenoid Adjustment: Loosen the screws that retain the
SOLENOID CHOKE to its bracket. Slide the SOLENOID
CHOKE in the slotted holes of the bracket to adjust axial move-
ment of the SOLENOID PLUNGER. Adjust SOLENOID
PLUNGER movement until, with the carburetor CHOKE PLATE
closed, the SOLENOID CHOKE is bottomed in its coil (plunger
at full actuated position). With the CHOKE PLATE closed and
the plunger bottomed in its coil, tighten the two screws.