Well, I think you are correct. You deffinately need to fix the leak before you get too far. Even if it is not the problem, the last thing you need is fuel leaking onto a hot engine. Is the leak coming from the top or the bottom? What type of carb do you have on it?

 

I know it might be a long shot, but did you check your jets? Depending on the carb you have, your jets might be clogged. These do not come in the cheap rebuild kits and, if bad enough, will not clean themselves in the Berryman's either. I had this happen one time a while ago. Replaced the jets and the engine fired right up. If you do not think that is it, try testing it wth another carb. At least that way you can eliminate the carb altogether if need be. Do you know anyone with a spare you can use?

 

Pull the air cleaner and use the throttle body on the carb to give it gas and short across the cylinoid, that way you can see were the gas is coming out of and actually look down into the top of the carb and see if anything really bad/obvious is going on.

 

Just rebuild the carb with new jets.