'91 225 Yamaha runs only at slow speed

[wasted-wanderer]

I seem to have a problem with my '91 225 Yahama engine. It starts up fine and idles well and will move the boat along at very slow speeds but as soon as i give it any more throttle it will stall out. The gas has been sitting without stabilizer for about a year. If the unit will start but doesn't seem to be gettting enough fuel at high speed, what is my best remedy? I put a marine grade stabilizer in the gas this past week, ran the engine at idle for about 15 minutes and let it sit with the fuel/stabilzer mixture in the carbs hoping this would help, it didn't. I've replaced the fuel/water filter and had no change. Do I have to pull the carbs to clean the floats and needles? Would this be the most logical area of cause? I would like to think that if we can put a robotic vehicle on Mars we should have some sort of additive/spray that would clear up a problem like this. All guidance, advice, help, etc. would be greatly appreciated.

 

[Ray Neudecker]

Re: '91 225 Yamaha runs only at slow speed

Time to go through the carbs and don't forget the fuel pumps also.

 

[Toniwdsl]

Re: '91 225 Yamaha runs only at slow speed

I agree with Ray .. I had the same problem with my previous motor where it will idle fine and run on a slightly raised rev but the moment u give it more it seemed to have a mind of its own and eventually stalls... turned out to be clogged fuel filter next to the engine.. hope that helps...

 

[bernieb]

Re: '91 225 Yamaha runs only at slow speed

Get rid of all the gas in the main tank ,start anew with fresh gas,then do the above suggestions.