Originally Posted by Finfan
The output of your magneto might be dropping off. If you have a spare one laying around try swapping it out and see if that solves the problem. I guess the CDI could also be a problem. Either way the increase draw from the lamp is killing your spark so it must be one of the two.
Thanks for tip, I hadn't thought of the increased "draw" that could cause the "kill".. but that makes alot of sense. I'll give 'em a try.. I have an engine still in the box unused...