Correct plugs or too cold?

Greg New Zealand

Petty Officer 3rd Class
Joined
Dec 7, 2003
Messages
98
Hello all. My 1977 Merc 50 is running Champion L 76 V plugs - these were in it when I bought the boat in Nov 2003. The boat was used for skiing but now for fishing.<br /><br />The manual says the plugs should be L 77 V - presumably they are hotter.<br /><br />I am concerned about plug fouling at lower speeds and a carbon build up. Just done a decarb and need to replace plugs anyway. This motor is the Lightening Energiser with Distributor & coil.<br /><br />What's the best choice?
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: Correct plugs or too cold?

I would run NGK plug # BUHW, which crosses to the L76V Champion plug, if you can get them. Mercs tend to do better with the NGK brand, as OMC products do better with Champions. Don't know why, but they do... But, if your Manual says 77's, that's what you should use. And yes, they are a hotter plug...
 
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