spark plugs

[mike12]

I have a 1973 Mercury 7.5hp outboard motor and would like to know which spark plug the factory calls for? Also I've heard that a gapped plug might be better in it and would like to know which one is best. Thank You for your help Mike

 

[roscoe]

Re: spark plugs

Looking at my factory owners manual for Merc 7.5 1973-1976.<br /><br />It says Champion L78V

 

[WillyBWright]

Re: spark plugs

You can use an L78C conventional design plug gapped at .040". They do a bit better at trolling speeds. The Vs definately do better at higher RPMs. It depends on how you use your motor.<br /><br />Proper English question. Is it "a" L78c or "an" L78C? On paper I'd think "a" L78C, but speaking I'd think "an" ell-seventy-eight-cee. Any English professors out there?

 

[mike12]

Re: spark plugs

Thanks for your help! Ido a lot of trolling think I'll try the L78C mike12