Thanks for the flax info. That problem could be a few things. Does it run fine while cruising? When you say cool down, does it run hot when cruising? temp? How old is cap, rotor, wires, plugs, ignition coil? I had an issue with my port engine hard starting, and it turned out to be timing was off 10 degrees. would run fine otherwise. Fuel water separators good? Fuel filter inside carb? Mine was full of crud.