Week spark on magneto bike

[Jordan]

The factory manual describes some tests for the stator and rotor of 40W alternators.
Rotor test involves spinning it to 3000 rpm.
Just an idea: Temporarily rig up a Kettering system (battery/coil) to provide sparks so you can run your engine to do the tests?

[Nick]

Ditch the stock ignition coil and swap for a later Japanese bike coil from a magneto bike. (Or a at least wire one up and see if there's a difference.)

The magnetism in my MKIII flywheel was weak, so I got it re-magnetized. Don't know who can do that now.

Also, make sure you've got either a fixed (non-advance) points cam, or the proper one for the magneto engine.) The dwell is very different for the battery models.

[Moto Chuck]

Ditch the stock ignition coil and swap for a later Japanese bike coil from a magneto bike. (Or a at least wire one up and see if there's a difference.)

The magnetism in my MKIII flywheel was weak, so I got it re-magnetized. Don't know who can do that now.

Also, make sure you've got either a fixed (non-advance) points cam, or the proper one for the magneto engine.) The dwell is very different for the battery models.

Have been too busy to work on the bike lately but am trying to get back to it.

I do know where there is a remagnetizer for the Ducati single mag buckets but that will require taking off the left side of the engine. Don't want to try that till I have exhausted the other possible causes.

My 1967 has a point cam with an advance built in.

As I said earlier, the bike ran well when I put it away back in the day. This is not a bike that has had unknown parts and pieces cobbled together that I don't know about.

[dsmess]

You might try temporarily grounding the alternator white wire. Make sure you have a low resistance connection to the engine case. This will eliminate the stoplite and bypass switch wiring. The stock coil should work, but a Honda C100 AC coil is better.

Dave M.