33
IGNITION SERVICE
SPARK PLUG SERVICE.
Spark plugs should be cleaned
and adjusted periodically. Check point gap with wire
feeler gauge (.030" - .762 mm) and adjust gap. Replace
if points are pitted and burned or the porcelain is cracked.
Refer to Master Parts Manual or Micro-Fiche for correct
replacement number.
If spark plug fouls frequently, check for the following
conditions:
1. Carburetor set too rich.
2. Choke not opening fully.
3. Poor grade gasoline.
4. Clogged exhaust system.
5. Incorrect spark plug.
6. Improper oil fuel ratio.
7. Inconsistent spark.
NOTE:
Ensure cleaned spark plugs are free of
all foreign material before installation.
FLYWHEEL REMOVAL AND SERVICE.
To remove
flywheel, use a strap wrench Part No. 670305 to hold
the flywheel and remove the nut by turning it in the
direction opposite of crankshaft rotation.
STRAP WRENCH
670305
FLYWHEEL PULLER
670306
NOTE:
A KNOCK-OFF TOOL IS NOT RECOMMENDED
FOR ENGINES WITH A BALL BEARING ON THE
MAGNETO END OF THE CRANKSHAFT.
NOTE:
If a knock-off tool is used, the pounding may
cause the ball bearing to dislodge from the shroud
base and force the lower thrust face of the crankshaft
against the cylinder thrust face. TO CORRECT THIS
CONDITION RAP SHARPLY WITH RAWHIDE MALLET
ON THE P.T.O. END TO PROVIDE CLEARANCE
BETWEEN CRANKSHAFT AND CYLINDER THRUST
FACE.
BALL BEARING
MUST HAVE
CLEARANCE
NOTE:
Do not attempt to remove flywheel using a
jaw type pullers on the outer diameter of the flywheel
or flywheel breakage will occur.
On engines with cored holes (not tapped) use flywheel
puller part No. 670306.
If the flywheel is difficult to remove from the crankshaft
because of rust, etc., the use of a propane torch can
be helpful. Heat the area immediately outside of the
crankshaft. The aluminum alloy in the flywheel should
expand enough to break the seal away from the steel
crankshaft.
FLYWHEEL MAGNETS.
The magnets in the flywheel
rarely lose their magnetic strength. If magnets are
suspected to be faulty, place the flywheel upside down
on a wooden surface. Hold a screwdriver by the extreme
end of handle with the point down. Move the blade to
within 3/4 inch of magnets. The magnets should attract
the screwdriver blade against the magnet.
3/4" (19
mm
)
MAGNETS
SCREWDRIVER LENGTH
APPROXIMATELY
6" (15.24 cm)
Summary of Contents for AH520 -
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