[Seachaser 186]

I have a 98 model Yamaha 90 hp that has been a dream. It's never given me any problems. However, I recently noticed what seemed to be fuel leaking out of the carbs when I tilted the motor up after running. I don't see it dripping, I just see a fuel /oil slick around the motor when I tilt it back down. Now it's not wanting to idle. It keeps coughing and spitting and quits. If I idle it up beyond 1000 rpms it will run but still is not smooth. The high idle just keeps it from dying. It will start back up immediatly but will die again at idle within 10 to 15 seconds. If I put it in gear and take off, it runs perfect. Would this be a situation where the carbs need rebuilding? In case anyone is thinking ethanol or water, I have put a new fuel line and a new 10 micron fuel/water separator on the boat. Any suggestions would be appreciated.

 

[Ocean Master]

It sounds like the floats needle valves are sticking. Time for quick carb rebuild.

 

[Sig]

I am having the same problems with my Mercury 90 4 stroke. If you find a fix let me know. I just posted a similar post before I saw yours.

 

[Seachaser 186]

thanks O.M. that's what I was thinking. Does anyone have a recommendation on a Yamaha mechanic? I heard Emerald Coast Marine closed down and Kenny Mann was well respected.

 

[Sequoiha]

Yes but he is still around, I am at barber marina now, still working on engines, a bit out of the way but well worth your drive for perfection...

 

[DOUBLE "D" & LV]

We will be glad to fix it for you if needed. One other item it may be would be the fuel pump leaking into the block from a ruptured diaphragm.