Are you using a factory pick-up?
Cuz they are color-coded; your SBM PU needs to have one orange wire for CW rotation.
The slanty/440 pick up is wired for CCW rotation.. It will still send sparks at low rpm and will run, sorta, but as soon as you try to bring up the rpm, the spark has a mind of it's own. I think this one IIRC has a purple wire; in any case don't use a purple-wired PU.
