TEST OR INSPECTION
Step 3. Check magneto breaker points for proper gap.
a. Remove four screws and lockwashers that secure the end cover on the magneto; remove the cover and gasket.
b. Tag and disconnect the shielded spark plug cables from the magneto end cap, by unscrewing the shield
c. Using the hand crank, turn the engine over until the movable contact is on the high portion of the cam. Insert a
feeler gage between the contact points. The required contact gap is 0.015 inch. Loosen the stationary contact
mounting screw and adjust the position of the stationary contact to provide the required gap when the cam holds
the contacts fully open. Tighten the stationary contact screw to secure the adjustment.
d. To replace the breaker points, remove four screws and lockwashers that secure the end cover on the magneto;
remove the cover and gasket. Remove four screws that secure the end cap and gasket to the magneto; remove the
end cap and gasket. Remove retaining ring and remove the movable contact from the pivot. Remove screws and
washers that secure the stationary contact and cam wick to the magneto, remove the stationary contact and cam
e. Apply a light coat of grease on the magneto cam. Position the new stationary contact set on the magneto
bearing support; secure by installing the cam wick, screws and lockwashers, do not tighten screws. Position the
movable contact on the pivot of the bearing support; secure with the retaining ring. Refer to step 3, para c for
contact set adjustment.
Step 4. Check for a defective magneto capacitor.
a. Remove two screws and lockwashers that secure the capacitor to the lower front of the magneto; remove the
capacitor and packing.
c. Position capacitor and packing in the magneto; secure with screws and lockwashers.
Step 5. Check for defective spark plugs.
a. Tag and disconnect the shielded spark plug cables from the spark plugs. Using a spark plug wrench, remove
the spark plugs.
Dry cleaning solvent, PD 680, used to clean parts is potentially dangerous to personnel
and property. Avoid repeated and prolonged skin contact. Do not use near open flame or
excessive heat. Flash point of solvent is 100F-138F (38C-59C).
b. Wipe the exterior of the spark plugs with a cloth dampened with dry cleaning solvent (fed spec. PD 680) dry
c. Check the ceramic insulator for cracks, porosity, and other damage.
d. If the electrodes of the spark plugs are not too badly burned, remove the scale and other deposits from them.
This can be done by a sand blast type cleaner or with a contact file.
e. Inspect the electrodes for severe burning, cracks, and other damage. Replace any spark plugs whose condition
f. Make sure all spark plugs are gapped to 0.025 inch before installation. Install and torque the spark plugs to 35
3. ENGINE TURNS OVER BUT FAILS TO START (GOOD SPARK).
Before proceeding, carefully review the step-by-step starting procedures detailed in paragraph 2-
3. Omission of one or more steps can prevent the engine from starting.
If engine is cold, check for proper choke control Operation.
Be sure choke control is all the way out, and is not binding or stuck only part-way closed.
If engine is hot, check for flooded carburetor.
Open the flood relief drain cock on the underside of the carburetor, near the air cleaner inlet hose and allow excess
fuel to drain. Restart with both throttle control and choke control in all the way.
Check for dirt or water in fuel filter bowl.
a. Close the shutoff valve on the fuel strainer.
b. Loosen the bail nut and swing the bail aside. Remove the glass bowl and gasket. Empty the contents of the
bowl and wipe it dry with a clean dry cloth.
c. If engine operation indicates that the filter element is contaminated, replace it with a new one.
d. Install filter element in strainer housing and install gasket and glass bowl. Swing bail into position and tighten
the bail nut.
Check for restricted fuel line.
Inspect fuel lines for breaks, kinks, or pinched sections. Repair or replace as necessary.
Check fuel pump for operation.
a. Disconnect fuel hose at carburetor. Push and hold starter button for a few seconds. Gas should be ejected from
the fuel line. Replace a defective fuel pump.
b. Disconnect fuel hose at fuel strainer. Remove fuel strainer from the fuel pump. Remove two capscrews and
lockwashers and remove the fuel pump and gasket.
c. Position a new fuel pump and gasket on the engine and secure with capscrews and lockwashers. Install fuel
strainer on the fuel pump and connect fuel hose to fuel strainer. Connect fuel hose to carburetor.