Yamaha 3hp revs keep going-up

[Boating_Al]

My brother-in-law has an Yamaha 3hp that we took out this weekend(Columbus Day) and we could not use it, it started fine?pulled the choke & give it a pull & started-up, but when the choke was pushed back-in the motor would start to rev-up like it was going to exploded.


Help?what it could be?the motor worked fine two weeks ago.

 

[robert graham]

Re: Yamaha 3hp revs keep going-up

Sounds like a problem with the throttle cable. remove shroud, operate throttle/carb linkeage for binding/problems. It should operate very freely, opening and closing carb. Good Luck!

 

[Boating_Al]

Re: Yamaha 3hp revs keep going-up

Actually the linkage operated just fine, we took the carb off & sprayed with carb cleaner (did nothing)?I?m thinking it?s a victim of ethanol. May have to rebuild the carb.

Thanks...

 

[99yam40]

Re: Yamaha 3hp revs keep going-up

has to be a stuck butterfly to be getting enough air to rev that high