I have a 1999 Yamaha 90HP 2 stroke. It has been running fine until I noticed at top speed, it has been wavering like it isnt getting enough gas. I have cleaned the carbs (squeaky clean), changed water separator and fuel filter (both clean), changed spark plugs, and run Yamalube shock treatment in my gasoline. I am pretty sure it is a fuel issue because it seems to be affected by people in the boat causing more fuel to be used. It runs great at low speeds up to 3/4 speed. When fuel is at its highest demand, after about 30 seconds, it starts to waiver. I have to drop down to neutral and then I can resume normal operation. Any suggestions are appreciated. Perhaps a faulty fuel pump????
