Yamaha 225 loses rpm's

[Greenwing]

I have 1993 Yamaha 225 the other day launched my boat ran to a spot to fish it ran fine on the way back it was running fine then it started losing rpm's as I gave it more gas it didnt change much come to a complete stop it was running fine no miss or anything throttled up a few times took back off it ran fine. <br /> Three days later launch it and headed down the lake after about three minutes of running it done the same thing but this time it would run at 5200 rpm's the first time wouldnt go any higher than 4400. After reaching where I was going no more than four minutes later fished for around two hours it ran perfect the rest of the afternoon.<br /> Any suggestions would be apreciated I wont have it out until Sunday if there are some simple things to check between now and Sunday. Today I changed the water/fuel filter and plugs.

 

[Greenwing]

Re: Yamaha 225 loses rpm's

Talked to a local mechanic he said his first guess would be one of the three fuel pumps but he said fuel pumps usually works or they dont. Does that sound right.

 

[rodbolt]

Re: Yamaha 225 loses rpm's

nope<br /> the pumps can leak fuel into the crankcase. I think the top pump on that motor is for the enrichment circuits. does the upper pump have two shiny metal solinoids labeled A and B. ?

 

[Greenwing]

Re: Yamaha 225 loses rpm's

Yes it does, I have decided to have the pumps rebuilt regardless does the top need to be rebuilt also. I was checking on boats.net they listed a complete fuel pump assembly for 30.81 is that the complete pump if so would that be cheaper than paying someone 65.00 hr to rebuild them. The part no is 6E5-24410-03-00

 

[phreddp]

Re: Yamaha 225 loses rpm's

Did you find out what the problem was?
I'm going through the same type of problem.