I've sanded the flywheel and armature: no spark.

I've replaced the armature/coil: no spark.

It must be the cut-off wire. Does anyone know where the wires should go from and to in this circuit. I've disconnected the armature spade connection and it gives no spark. How do I get a complete circuit without cut-out?
Thanks,
David

dbmead, August 2010

Yes - with the spade terminal completely disconnected, there should be a spark. If there isn't, the coil is duff, OR (rarely) the flywheel magnets have de-magnetised. Usually this only occurs if subected to extreme heat - such as using salvaged parts that were fire damaged.

Phil Saunders, August 2010

Thanks, Phil.
Isn't there some other circuit that must be completed, that uses the spade connection, in order to get a spark? Are you saying with the armature installed, but the spade connection completely open, there should be a spark when the plug threads are touching the frame?
Is there any way for me to test the armature? The plug is new, the coil is a new-used one, from ebay.

dbmead, August 2010

If you have disconnected the spade terminal on the coil, then the cut-out circuit is not involved.

If you still have no spark, then either you have a duff coil, or the plug is shorted (not unheard of - even if new)

phil_saunders(a)bigfoot.com

Phil Saunders, August 2010