1994 merc 5.7 with a carter bogging bigtime under accel, fine elsewise

gerard143

Cadet
Joined
Apr 4, 2010
Messages
24
i have a regal valanti 222se with a 5.7 merc in it. it has a 4 bbl carter 9961s carb. entire tank of gas is fresh, fuel seperator replaced, checked the vent and ran it with filler cap off just to make sure it was vented.

carb was rebuilt before i ran the boat this season. Now i wish i ran it before I rebuilt the carb because idk if the issue is in the carb or something else is acting up and the carb is fine. when i rebuilt the carb nothing really look bad other then the accelerator pump seal for the bore was tore up a little.

Anyways heres whats going on. this will be my third summer with the boat. since i bought it the last two summers in a throttle range i dont use to often (a little past half doing maybe 35) it would run a little erractic. kind of surging. any other throttle range it was fine. One day last season the boat did what it is doing now all the time. What happens its it bogs bad under acceleration and takes forever to get up to speed. once its there it'll hold 50mph all day long.... drop the throttle it'll run 40, 45, 30 etc. starts up fine... idles up fine. just under acceleration i have this issue. the floats are set properly in both positions, the accel pump is set properly, the choke pull off linkages (manual choke) are set right with proper gap on the plate. it does open once the motor gets warm.

i haven't checked the anti syphon valve or the fuel pump. but if once im up to speed it can run all day long at 50 it leads me to think maybe those aren't the problems.

idk. what does everyone think? next time im out i will bring a 5gallon can and run it directly off that to bypass the valve to see what happens. then i'll get a guage and hook it inline and test pressure.
 
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