mercruiser 140 stalls at 1500 rpm

[srrwood]

First post. I have been observing for sometime and have gotten a dead engine going because of this board.

Anyways I have replaced head gasket, coil, ballast resistor, condensor, points, plugs, cap, rotor, drained fuel, boiled carb was very careful with all settings. Mercarb, by the way. Set points, timing. While boiling carb power piston fell out. I stuck it back in. New power valve in kit.

Engine idles well. During acceleration (fast or slow) it dies at 1500 rpm. I have to feather throttle bak to idle and in a few times, then she will 'catch' and take off. I have heard of a thick base gasket for carb that could solve problem. Anybody have a part number or source?

Also can see solid stream of fuel from both venturis when pushing throttle forward.

Help!

 

[Howard Sterndrive]

Re: mercruiser 140 stalls at 1500 rpm

not sure what you mean by "boil", but it sounds like you need to rebuild the carb. and yeah, the thicker 27-807982 base gasket helps.
You reused your old one?

 

[Bondo]

Re: mercruiser 140 stalls at 1500 rpm

Ayuh,... By the sounds, it appears the Hi-speed jets are Plugged...

 

[srrwood]

Re: mercruiser 140 stalls at 1500 rpm

By 'boiling' carb I mean rebuilding it. I boiled the bare frame of the carb to clean it. I read about that on this board somewhere. I used a rebuild kit also. If the high speed jets were clogged wouldn't it just die completely? It will go full throttle just fine if I feather the throttle back to idle a few times and then go. It seems to me that it would be in the transition circuit of the carb.

This past weekend the weather was crap so I didn't go out on the water but I did eliminate a few possibilities. Its not the advance, that was fine. The fuel pump tested fine also. I took the top off the carb and the power piston seems good too. I made a spacer out of polycarbonate to raise the carb off the manifold, but now I have the thick gasket part number (thank you) ill stick that in.

On the trailer the die at rpm seems to be 2200.

I also double checked oil level (I read high oil level could cause this.)

Anymore suggestions would be awesome.