merc 5.7 idles ok dies when throttle opens

[oldseaox]

Carb eng. will idle but dies when throttle is opened, 1997 eng just replaced with Jasper rebuild. 2brl carb, all fluids and pressures ok. Have 5 hrs on eng. Suggestions???

 

[Don S]

Re: merc 5.7 idles ok dies when throttle opens

Is the accelerator pump in the carb working?

 

[Bondo]

Re: merc 5.7 idles ok dies when throttle opens

Carb eng. will idle but dies when throttle is opened, 1997 eng just replaced with Jasper rebuild. 2brl carb, all fluids and pressures ok. Have 5 hrs on eng. Suggestions???

Ayuh,.... What happened to the old motor,..?? Sounds like this 1 is starvin' for fuel....

 

[akorcovelos]

Re: merc 5.7 idles ok dies when throttle opens

what is initial timing set at? I assume it running TB ignition?

 

[Oshkosh1]

Re: merc 5.7 idles ok dies when throttle opens

Suggestions???

Rebuild the carb if it wasn't done with the new motor.
Check the fuel pump/line/filter for obstructions.

 

[NHGuy]

Re: merc 5.7 idles ok dies when throttle opens

Did the Jasper motor come with a carburetor, and did it come with an intake manifold? If you have 2, try the other one(s). If you have only one you ought to do as said above. Check for fuel starvation & bad carb. Check around the carburetor base and intake manifold for air leaks. Try spraying carb cleaner around those areas, if the engine speed fluctuates there's a leak where you sprayed.
Jasper is a reputable outfit, I bet the motor is not the problem.

 

[oldseaox]

Re: merc 5.7 idles ok dies when throttle opens

I don't suspect eng, sounds good and holds good pressure. Going to check timing in the AM (just because its easy to check it first) and then the carb will come off. Changed the fuel filter and found a small amount of trash, a very small amount. Acel pump appears to work just fine. Have already tried the spray around the intake and carb base but no effect, it idles smooth anyway. As soon as the butterflies crack it dies.

 

[oldseaox]

Re: merc 5.7 idles ok dies when throttle opens

Timing ok, pulled carb and as soon as I pulled the horn I saw the problem. Power valve in bottom of float chamber, where all the trash and water goes. Bought a kit and rebuilt it, runs fine now.