1993 Mercury 150 Problems

[Gamecock1]

I have looked and cant find a fix to my problems. I have a 1993 Mercury 150 with the oil injection removed. The engine smokes a lot at idle and while revving. The engine is stuttering on take off but runs good at full throttle. Also the engine is surging at cruising speeds(1/4-1/2 throttle). So far I have rebuilt fuel pump and carbs, changed plugs, and checked compression. Nothing has fixed the problem. Please help!!

 

[Chris1956]

Well, I would have thought your problem would be a tear in the fuel pump diaghram, but you say you fixed it. You might pull the pulse line off the fuel pump and pump the primer just to make sure the diaghram is good.

Maybe the carbs are flooding? Are the floats set correctly? Surging could be an air leak in the carb base gaskets. You might check to make sure bolts are tight.

 

[Faztbullet]

Check the recirc valves......

 

[Gamecock1]

Well, I would have thought your problem would be a tear in the fuel pump diaghram, but you say you fixed it. You might pull the pulse line off the fuel pump and pump the primer just to make sure the diaghram is good.

Maybe the carbs are flooding? Are the floats set correctly? Surging could be an air leak in the carb base gaskets. You might check to make sure bolts are tight.

Just took the fuel pump back apart and everything looks good. Carb bolts were tight with new gaskets. I have carbs off now rebuilding. Will retest tomorrow. Thanks for the ideals.

 

[Gamecock1]

Check the recirc valves......

What are these and where are they located. Lol I'm an ase certified auto tech but new to marine engines.

 

[Gamecock1]

Carb build did not fix the problem. Still stumbling and surging. Any help please!!!!!