Did you also change the filter "sock" that is part of the pick up tube in the tank? It may be cogged to the point that it won't let sufficient gas through to keep up with what the engine uses but will let enough "soak through" when the engine shuts off to allow it to start and run a few minutes. I suppose the same theory could apply to an in line paper filter too. I once heard of a rubber line which had collapsed internally cutting off fuel flow intermittently. I agree with a lot of the other answers in that its most likely not ignition-related. The engine is using the gas faster than it can get more whatever the cause. I also agree that he float should not let fuel through in the "full up" position. Once your real problem is fixed, this will lead to flooding and/or fire. The float is there to keep the fuel at the proper level in the carb. and it can't do that unless it can shut it off momentarily when its reached that level. Good luck. ________________________________________________________________ GET INTERNET ACCESS FROM JUNO! Juno offers FREE or PREMIUM Internet access for less! Join Juno today! For your FREE software, visit: http://dl.www.juno.com/get/web/.