I got this motor running last fall, right before winter so I never got to take it out on the water. The motor sat for at least ten years. Be fore I got it. I replaced the water pump, rebuilt the carb, and replaced the head gasket. Compression is 100 on the top and 90 on the bottom. I ran it today and it seems to backfire/ miss for about seven minutes or so then runs great after it warms up. Idles right down to a tick, and starts on the first pull. It was the same thing last year when I put it away for the winter. This was my brother in law's Dad's motor. He has since passed away. My brother in law says that as far as he can remember it always did that every time his dad took him out. I can totally live with this situation because once it is warmed up it runs well, but what do you think would cause this? I was in the carb three times to try to fix this so I doubt it is carb related. Like I said I can live with it, but it would sure be nice not to have to. Thanks
