mercury 9.9 idle and midrange problem

[dave1948]

I have a 1998 merc 2 cycle. Presently It stalls at idle a and back filres through the exhaust intermitantly at just below mid speed. I can set the idle at the dock and run it forward gear and it runs great. When I leave and change speeds the engine slows and stalls. to get it restart, I have to put it in gear and put it at full throttle than crank it. I have taken apart the carb and rebuilt the prime system I also replaced the carb mounting gasket. Lately I am running it rich wich gives me a rough idle but the engine doesn't stall. I am wondering if this could have to do with the bleed system or the reed valves. I have adjusted the timing with a light and done everything that I can think of. Any help would be appreciated. I bought this engine new and it's been nothing but trouble.

Dave

 

[Laddies]

Re: mercury 9.9 idle and midrange problem

Its a lean condition is the float a little low?

 

[rainycity1]

Re: mercury 9.9 idle and midrange problem

My 9.8 did the same kind of thing and it turned out to be one of the coils. Remove the coils and there is a little ground wire on the back side. Check continuity between that wire and the end of the spark plug wire. One of mine had continuity and the other did not. I bought two used ones off ebay and one of those was open too. I was told by an outboard mechanic that those coils are a common problem with mercs. Good Luck.