92 Yamaha 40 Precision Blend Running Rough

[PeteB88]

I have this motor on 13 Whaler and it runs rough WOT - never smooth at low to mid Rs but great at WOT since I have owned it. I use Yamalube and Seafoam. I believe the carbs need to be rebuilt/cleaned and want to learn to do myself. I bought Chilton and Seldoc manuals and they are not specific re: this motor. I hear rodbolt is the man - please advise, I am ready to learn. 2) I saw some info on Precision Blend system in forum. Sometimes I think it's getting way too much oil - smokes at low Rs - what is the deal?

Thanks!!

 

[PeteB88]

Re: 92 Yamaha 40 Precision Blend Running Rough

Forgot to clarify - motor started running real rough at WOT end of season, cleaned carbs w/ Deep Creep, Seafoam, good gas. Thanks

 

[JUSTINTIME]

Re: 92 Yamaha 40 Precision Blend Running Rough

buy a factory manual

 

[Ray Neudecker]

Re: 92 Yamaha 40 Precision Blend Running Rough

Likely will have to disassemble and properly clean and rebuild carbs to cure the problem.