spark plugs

[crazyray2]

79 model 80 hp mercury ....changing plugs...book calls for a L78V which is a surface gap plug...someone has installed L77JC4 what are the advantage of these disadvantages?<br /><br />------------------<br />If you dare go fast<br />If in doubt go fishing

 

[12Footer]

Re: spark plugs

Go back to the book's recommendation.<br />I don't know if the 2 are directly interchangable, but why take the chance?<br />I do know the JC4 is used on smaller mercs with thunderbolt ignition (which is a hot ignition).<br />The gapless plugs work fine,with less fouling. But they will still foul,just not as fast.