1 Cylinder not firing correctly

[Etindoll]

I have an 87 Force 50, model 507Y8C. It will not plane out. Ive noticed my lower cylinder keeps flooding out, Ive pulled the coil wire off the plug and tested for spark and it seems to be sparking fine. Any ideas would be greatly appreciated.

 

[kax2000]

Re: 1 Cylinder not firing correctly

Have you done a drop test on that cyl? (with new wires & plugs w/proper gap)?
Compression check on both?

 

[roscoe]

Re: 1 Cylinder not firing correctly

Sounds like a torn or damaged fuel pump diaphragm.
It will leak fuel directly into the crankcase and foul out the bottom cylinder.

Rebuild the fuel pump with a kit from a Mercury dealer, comes with instructions, cost is about $15.