1994 yami 250hp wot problem

I have twin 1994 yamaha 250 txrs outboards on my boat. The right motor runs strong up to 5700 rpm and the left is having problems at wot it will go to 5400 rpm. They used to both hit 5700. When I gun just one motor at a time the right runs strong to 4300 by itself and the left feels sluggish and hits 3700. I ran all new fuel lines , new fuel fiters and rebuilt the carbs. It has good response off idle but just doesnt have the power. like the right one. good compression 115 to 120 all cylinders. The next step I am guessing is the timing not advancing for some reason. I hooked up the diagnostic lamp to the motor and no codes came up. Any help would be appreciated

Re: 1994 yami250 wot problem

I am trying to figure a very similar problem. I am on the fifth mechanic and the carbs have been rebuilt three times. I guess I am going to "shotgun" repalce electronic parts and sensors till something works.

Re: 1994 yami250 wot problem

Additionally, the problem engine appears to have a flooding problem that the carb jobs never fixed. The electric transfer fuel pump was replaced, and one of the engine fuel pumps. New plugs and wires. V76 engines.

Re: 1994 yami250 wot problem

I know the frustration you are going through, I rebuilt the carbs , all new fuel pumps, new tstats, new filters, new hose from tank to carbs, I dont know what else I can do to solve the fuel problem. It also surges a little drops maybe 300 to 400 rpm then goes back to normal. The only thing left is a sensor but I have the diagnostic light and it is not throwing any codes.