1978 Merc 90 problem

[cwcfishstix]

The engine starts and runs fine at slow speed but if I run a few minutes at slow speed and then gas it, it stalls and won't get going. If I slowly increase speed then it will get up to full speed and seems to run fine. Any thoughts?

 

[achris]

Re: 1978 Merc 90 problem

Hi cwcfishstix,

The most common reason for that particular symptom is the ide mixtures are set slightly lean. The quickest way to check is the next time you're out, as you open the throttle and the engine starts to die, quickly activate the choke (push the ignition key in or press the CHOKE button). If the engine recovers and takes off the way it should the fix is just as easy. Richen the idle mixtures slightly. You have 3 carbs on that engine, at the front of each cab near the top, is a small brass screw. That's the idle mixture screw, turn it counter-clockwise about 1/8 to 1/4 turn. The engine should be working properly now.

Chris......