Motorcycle Repair: 1962 honda trail 55, cast iron engine, fly wheel

Question
No spark at plug, no spark at points. the 6 volt battery is
new, does it have enough juice to pop at the points? why 2
coils? this is a cast iron engine. Does the fly wheel need to
be on to get a spark?


Answer
Sam....   Use the C100 wiring diagram here:
http://www.oldmanhonda.com/MC/WiringDiagrams/MCwiring.php#class

This is a self-powered magneto ignition, not requiring a battery to make spark. There is a primary ignition coil under the flywheel and the secondary coil above that connects to the spark plug.

The flywheel MUST be installed, as the points cam is part of the inside of the flywheel. The magnet inside the flywheel is what causes the primary coil to generate some low voltage, which is transferred to the secondary coil.

Clean the points, set them to OPEN at the F mark on the flywheel/indicator mark on the engine case.

http://www.dansmc.com/magneto1.htm

Bill Silver