I have a 1989 9.9 four stroke. Lots of gas gets in to the bottom end. It starts good, runs great for hours at a time, than starts fouling plugs. The bottom plug is the first to go. I have to change oil often, which is full of gas. When I'm done running the motor, I disconnect the fuel line, until I am ready to use it again. Could this be a bad needle and seat , or accellerator pump issue?
