Sorry if this is a real bonehead newbie question, but I have leading spark and I have fuel , but no trailing spark - igniter problem I expect, but I would have thought it would start at least on just the leading spark.
Don

 

In theroy, as far as I know, it should start on just the leading spark. Although, if its not starting, I would investigate the no trailing spark more just in case. Or maybe you actually have them backwards. Leadings are the bottom plugs, just so you know .

~T.J.

 

I too was having problems with my trailing plugs. The connections on the ignitor were corroded. Nonetheless, it started fine with just the leading plugs, however sometimes it took a few turns to get it started. In fact, I drove it for a couple of weeks with just the leading plugs, however the trailing plugs were fouled out by the time I figured out it was the igniter.

 

Yelp it will still run, on later models if the trailing doesnt fire, no tach