please help 1990 mercury 150 please help

[crphead]

this motor will run fine from ramp when i accelerate once it gets warm and back off throttle does not want to go wide open again but once and while it will catch and go problem only seems to happen when motor is warm not cold have replaced fuel system, plugs ,rebuilt carbs ,fuel pump diaphram everything but fuel lines could it be the trigger or power pack or any other ideas please help thanks

 

[Faztbullet]

Re: please help 1990 mercury 150 please help

Take a timing light with you and when engine acts ups remove cowling and check spark on all cylinders, it sounds like a stator failing. Also check your rectifier/s as if bad they can cause a stator to shut down from overheating.

 

[CharlieB]

Re: please help 1990 mercury 150 please help

Also check the throttle and timing levers for smooth operation without sticking, if the timing lever sticks before reaching WOT full advance, motor performance will fail until the timing fully advances.