I bought a new 2 stroke Yamaha 4 in the Bahamas two years ago. Last summer it began stopping as if it were out of fuel every couple minutes. Waiting a couple minutes allowed a restart, but it would quit again. Knowing the problems with gas these days, I dissembled the carb and cleaned several times, checked and then replaced the little fuel filter (expensive in Europe) and then discovered the fuel prefilter at the bottom of the tank. Cleaned that but still no joy. Of course I always run the carb dry when I shut it off and use a fuel treatment with every fill-up.

So, near the top of my "to do" list before setting out this year, I went through it again and finally found the cause. The fuel valve that selects the tank on the engine or an external fuel tank and also shuts off the fuel has a rubber seal for the valve with small round holes to let the fuel through. It appears that today's gas caused the rubber to swell and thus just about close off the small round holes and thus the fuel flow. A few minutes with a sharp knife, a larger hole again, and the outboard runs great after a few minutes of treated gas flowing through the carb.

I wish I could just buy old-fashioned fuel that doesn't cause these kinds of problems.