1980 Mercury 50hp Fouling Plugs

Joined
Jun 20, 2007
Messages
9
I have a 1980 Mercury 50hp that goes through spark plugs like crazy. I would guess I probably get 15-20 hours run time before one starts giving me trouble. My oil/fuel mixture is at 50-1. I'm running the gapless plugs. (At least I think that's what their called). I take the plugs out and they are covered in a oil residue. What is causing this? How do I fix the problem? Thanks in advance for the help. :)
 

Barnacle_Bill

Admiral
Joined
Feb 8, 2004
Messages
6,469
Re: 1980 Mercury 50hp Fouling Plugs

Do a compression check and be sure you are using TCW-3 rated oil. The last time that happened to me it was because I was using cheap K-mart oil.
 

jmburock

Petty Officer 2nd Class
Joined
Aug 25, 2005
Messages
174
Re: 1980 Mercury 50hp Fouling Plugs

1) Make sure you have a good strong spark at all the cylinders.
2) Make sure you are pouring in the oil then the gas then mixing.
3) I had your problems when using cheap oil, switched to Quicksilver Premium Plus- helped.
4) Make sure you are using the mixing cylinder with the gradations on it to get an accurate 50:1 ratio.

If this all fails to rectify your problem, look into compression...
 
Joined
Jun 20, 2007
Messages
9
Re: 1980 Mercury 50hp Fouling Plugs

I will try switching oil and see what happens. I was not aware that a cheap oil could possibly do this. Also what should the compression be at if I have to check it? What is the minimum? Thanks for the help. :)
 
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