jamie, i had a similar problem with a 4ks of mine that was caused by a spread female contact...ooh that sounds bad...on the hall sender socket. intermittently it would lose the signal and the engine wouldn't fire. i used a scribe to pinch the contacts together and never had a further problem mike 86 5kcdtq, tap chip sjm spring 84 5ks 84 5ksw many cyclops bicycles