2002 Yamaha F15PLHA 15HP 4 Stroke Idle Issues

cobrien

Recruit
Joined
Aug 17, 2016
Messages
2
Hoping that someone can offer some assistance with my motor. I bought this motor a few years ago and it has never idled very smoothly. Lately it has gotten worse so I decided to see if I could fix it. I installed a carburetor rebuild kit in hopes that it would fix the issue, but it has not.

When starting the motor cold it starts up fine with the choke out and idles fairly smoothly. Once it reaches operating temperature (and the choke is pushed in) the RMP becomes inconsistent. If you rev the throttle it dies as soon as the RPM returns to idle speed.

I have thoroughly cleaned the carburetor and have verified that all of the orifices are clear of any debris. I have changed the fuel filter and have taken off and cleaned the outer cover from the fuel pump. The accelerator pump seems to be working fine.

Any ideas?
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,878
did you remove the air adjustment screw under the cap/plug when you cleaned the carb?
did you adjust that screw to spec in manual?
 

cobrien

Recruit
Joined
Aug 17, 2016
Messages
2
I did replace the air adjustment screw and returned it to the factory setting.
 
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