'92 Yamaha 150 surges at WOT

[stansmith]

First - Thanks to everyone for a great site - I have learned a lot from what is posted here. My motor runs fine at start up and idle but has developed an intermittent surge problem at WOT. Also - the max RPM's have decreased from about 5300 down to to about 4300. I have replaced the fuel filters and checked the fuel line(s) for air leaks. Did not find any leaks. To my knowledge the fuel pumps have not been replaced in a couple of years. Is it possible that the fuel pumps need to be changed out? New ones are pretty cheap. Should I clean the carbs as well? Thanks in advance for the help

 

[fishie1]

Re: '92 Yamaha 150 surges at WOT

I had a similar problem in that the engine would run WOT at 5500 and then after a short period of time drop to 4800. The mechanic chased it down to a fuel pump. Good luck.

 

[Ray Neudecker]

Re: '92 Yamaha 150 surges at WOT

fairly obvios fuel restriction. I would replace the pumps and rebuild the carbs. Fuel restrictions are a major cause of power head failures.

 

[stansmith]

Re: '92 Yamaha 150 surges at WOT

Ok, Thanks for the response. I will replace the pumps this afternoon. (easy) But I think I will have my local Yamaha dealer do the carbs. thanks again!