1989 100 HP Sea Ray / Mercury idling problem

[markvb]

I have a 1989 100hp Merc on a Sea Ray 160 that idles poorly. I understand this engine only idles on 2 cylinders, but I don't think that explains the rpms rising and falling suddenly. I pulled off the flywheel and found a broken magnet. I replaced the whole flywheel but the poor idling persists.

The video shows what is happening. No one is touching the throttle controls.

 

[racerone]

Open up the low speed jets on top 2 carburetors 1/8 turn at a time and try again.----Trim the motor down too.

 

[markvb]

I will try this. Thanks for the reply.

 

[Dave1027]

Basically what's happening is a lean condition which causes it to sneeze. In your video, how do you have the throttle set?

 

[markvb]

The throttle is set fully neutral. If I rev it up a bit, it doesn't 'sneeze' as much.

 

[racerone]

Have you tried opening the slow speed mixture needles yet ?

 

[mikeboston47]

markvb, i have a similar engine, the '89 mercury 115, 2+2, with the same prob, tried racerone's idea of backing out screws 1/8 turn counterclockwise, solved the problem, quick easy fix

 

[mikeboston47]

thanx for your insight racer one, i had a prob with my 89 mercy 115 2+2, didn't know it was called misfiring till someone at launch told me that was the name for it, looked all over for answers, i had new clean fuel , new fuel filter, had carb clean go thru a tank of gas, still sucked, till i saw you're reply to Searay 100hp queries(re; [h=1]1989 100 HP Sea Ray / Mercury idling problem)[/h] , have a video of mine that is almost exact same as his,voila works like a charm now, and now i can sell it with a clear conscience, thanks again