Reply To: Mercury force 120 misfiring pics of spark plugs

[Beno]

Ok sorry for the trouble guys.  As you know it was cylinder 1 and 3 black on the plugs. So I immediately traced cylinder one and three (and on this system they are brown and purple).

Course I immediately became suspicious because I know from experience that purple wires can look Brown after being on the engine for some time.

Upon further inspection  .. even though I could see there was a brown to brown wire connection: looking further there was a brown to purple lower.   So I took out my jackknife and scraped on the top brown and voila one micron thick layer of brown scraped off revealed purple. Ok HOW COULD IT HAVE BEEN RUNNING AT ALL?

Sea trials commenced.    She ran pretty good…

Id say it runs at 85% power for a 120hp.  I did not know what kind of gas might have been in the tank but i put in 10gals and 33oz of tcw3.. so if there was 5 gals in the tank.  Im kinda covered.

So now i have to try to figure out why it occasionally misses at high speed. But i really need to put some time in on the river to get a feel for it.  The new Hull numbers should be in tomorrow I think