2003 Mercury 125 2+2 fuel problem

[FishinRich52]

Hi All,

I have a 2003 Mercury 125 2+2 with a fuel problem.

All 4 carbs have been rebuilt and a new float in #3. New fuel lines from the tank to all carbs. Rebuilt fuel pump.

The #3 carburetor and sometimes the #4 carburetor (the ones without idle screws) will dump fuel out of the vent tubes at idle. #1 and #2 are fine.

I can NOT get the carbs to leak when I pump the primer bulb no matter how hard I pump it. (I figure this should test the needles and seats)
When the engine is first started, fuel will not leak. After running the boat around a bit and bringing it back to an idle fuel will start dumping out of the vent tubes. The engine will then stall as it gets flooded.

I am wondering if a reed valve problem could cause this (drawing too much air over the carbs at idle) or if anyone has any other suggestions?

Thanks
Rich

 

[racerone]

Reed valves are NOT the problem.----Revisit work on carburetor float valves.----Perhaps look at the accelerater pump.