Motorcycle Repair: 1982 yamaha maxim 750, float valves, step brother

Question
i got this bike from my step brother, he said when the engine gets warm the pistons fill up with gas and dont fire, it starts with one and works to three of the four pistons. i took it out for a decent length ride to my buddys house, shut it off, then about twenty minutes later it fired right up again and road good all the way home. but when i parked it and came back two or more hours later, there was gas all over the ground. my step brother says its the stater coils that are pumping too much gas and thats what we need to replace, what do you think?

Answer
Devan, if you have gas flowing out of the carburetor overflow tubes, the float valves are all leaking and not shutting off. Probably due to old gas in the tank that has formed water/rust and who knows what. Carbs need to come off for a good cleaning of all jets and air/fuel passages, new float valves and gaskets. Put in fresh plugs after you finish the carbs, as the old ones are probably permanently fuel fouled.

Bill Silver