Spark Plugs for Mark 55E

dbuffington

Petty Officer 2nd Class
Joined
Oct 1, 2007
Messages
127
Hi Folks!

We have a mid-50's vintage Mercury Mark 55E. It runs beautifully -- thanks largely to Lancaster County Marine -- but creates some RF interference with our VHF radio.

The plug specification in the original owners manual is a Champion J6J. However, the current recommendation seems to be a J8C.

I'd like to try resistor plugs to see if that reduces the RFI. Does anyone have a resistor plug recommendation?

Thanks!
Dave
 

dbuffington

Petty Officer 2nd Class
Joined
Oct 1, 2007
Messages
127
Re: Spark Plugs for Mark 55E

Alas, I now have an answer to my own question... The vintage Mercury service manual says that resistor plugs must NOT be used with four-cylinder engines with magneto ignition. Sigh :(
 
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