For many years I used to get motorcycle/moped flywheel mags apart by the
following method. You CAN do it unaided, but it's so much easier with a
friend.
Before you do anything else, mark the flywheel/crankcase to be able to
re-assemble it correctly if there is no keyway. I used to mark top dead
centre AND points opening, but it really doesn't matter as long as you have
a reference point.
Back off the flywheel nut but leave it in place on the shaft.. Some have a
captive nut and are self extracting. Obviously, if yours has this feature
you can stop reading now, but it was such a good idea they stopped doing it!
Figure out where the coils are and avoid them. Place a short round ended
tyre lever under the flywheel rim where there is nothing to damage and apply
light pressure to the end of the lever. Light pressure, I said ;o))
Ideally, you should use a big socket that will surround the inside edge of
the flywheel, but you can use a drift of substantial proportions direct
against the inner part of the flywheel as close to the shaft end as possible
if absolutely necessary. Strike the drift a sharp blow once or twice and
the flywheel should magically come free, the loose nut preventing it from
falling to the floor. The nut will also protect the shaft end if you are
clumsy!
For my money, I'll never willingly strike the end of a shaft with a hammer
of any kind, lead, cloth, leather or whatever. Beyond the flywheel there may
be a ball race and a blow to the shaft can shatter the outer race.
The reasoning is that the blow will drive the flywheel slightly further onto
its taper and it will momentarily spring open to accommodate this. The
slight application of force at the flywheel rim has the dual purpose of
applying a twisting force and encouraging the female taper to continue to
relax as it looses contact with the male shaft.
And rest.
I stress that the force applied with the tyre lever should only be slight -
say enough to crush a fag packet.
Usual disclaimers!
Regards,
Kim Siddorn