Further to my irregular running on the MDD, as all simple tests have failed, is there a simple (for me!) way to test the mag when it's an intermittent problem? I believe it had been re-built before I purchased the bike, but I need to rule it out, just not sure how to test it without sending it away. Tappet adjustments were fine though it is running rich. 120 main 6/3 slide.
Phew!

email (option): alistair@jimpeet.co.uk

Don't know if it helps, but I ran it in the lathe at low RPM with the lights out. Gave me a clue of how it was sparking and its frequency.

email (option): unpob@yahoo.com

Alistair It's difficult to test the mag properly on the bike. The only indication you can get is by removing the plug and hold the bare end of the HT lead about 1/4"-3/8" away from the mag body. Now give the bike a good kick over. You should have a strong blue spark that should jump about 1/2". But better to remove the pinion and clamp the threaded end of the armature in a drill chuck and drive it fast in the correct direction. Now watch the spark for several minutes. Again this is only a preliminary test as the condenser will sometimes break down after it's got hot. Ron

email (option): ronpier@talk21.com

If I could seperate the wiring should it be possible to use a suitable 6v coil and bypass the condenser?

email (option): alistair@jimpeet.co.uk

I think that's a question for Noam Ron

email (option): ronpier@talk21.com

If you place the magneto in the oven for a short while to simulate it's operating temperature and then try spinning it and check the spark, my magneto reconditioner runs his mags cold for a couple of hours and then puts a heat gun on them to get them pretty hot and checks them for sparks when they are hot, I'd try making a jig of some sort powered by your lathe or a suitable electric motor and leave them running for a while and vary the temperature with a heat gun.

email (option): davmax@ntlworld.com