1999 Yamaha F100 - No Response w/ Throttle Up

MikeMM

Recruit
Joined
Aug 17, 2008
Messages
2
My '99 Yamaha Outboard F100 has been running great. Since Jan this year however, I've only run it approximately every 5-8 weeks.

Have just learned about the problems associated with storing ethanol in a marine environment.

Engine won't advance beyond approx 3200 RPM even at WOT.

Idles fine, starts up on first turn of the key...

Changed out the water-separator filter, inline filter, new plugs, and oil.

A friend told me to spray carb cleaner in each of the carb's drain plugs. All plugs drained fuel upon opening except the bottom (4th) plug - it was dry as a bone.

Fuel pumps were opened up - look fine, so I'm assuming I have a blockage somewhere in that bottom carb.

Any help or cost estimates to repair this?

Thanks - new to forum!

Mike
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: 1999 Yamaha F100 - No Response w/ Throttle Up

while the carb is apart to inspect the needle valve check the inline filter at the point where the fuel line attaches to the carb, each inlet has a filter unless someone has removed them.
 

MikeMM

Recruit
Joined
Aug 17, 2008
Messages
2
Re: 1999 Yamaha F100 - No Response w/ Throttle Up

Rodbolt - thanks for the gouge, I'll check for them.

Also think I'll replace the diaphragms in the fuel pumps - look to be originals.

MM
 
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