Mercury 9.8 Idle problems

[Rmoore45]

After fixing the spark problem, I got the it running and now it has a new problem that it didn't have before. When cold and idling low (as low as it can go) it sputters and sneezes then returns to normal idling, then does the same thing and dies. It does it frequently when its cold and occasionally when its warmed up. It seems like its intermittently losing spark on 1 or both coils, I don't hear spark jumping. It only does it at really low idle which is not really a problem but before it would idle low forever.

Thanks, Ranger

 

[jerryjerry05]

Re: Mercury 9.8 Idle problems

Hi Ranger. The idle should be about 750 in gear.
Sounds like the air screw is out of adjustment.
Turn in(gently)to the bottom.Then out 1 and 1/16th turn.
Start motor,run till warm.Then in gear and in the water.Turn the screw in till it misses/ stutters/coughs or stalls.Then out 1/2 turn.

 

[Rmoore45]

Re: Mercury 9.8 Idle problems

Problem solved, it was the top cylinder coil. I replaced it with another one that I had and so far no problems. I knew it wasn't the air screw because before I replaced the power pack and coils it was running fine. I must have a strong motor, with my laser tach I was getting 600-650 rpm in gear and 800 when not in gear.