Spark Plugs for 500efi Stock vs After market
 

Need to probably replace these things, got 100 hours on them. They don't misfire and boat cranks right up. But its probably time for new plugs, so is the stock merc ones good or should I go with something else?:rolleyes:

WILL

Will, I have read that there is no horse power gain available from a spark plug. But I have always liked the AC Delco Rapid Fire plugs. Had them in my HP500 carb last year and also in my truck. The part# for your motor RapidFire #1.

Eric

save a couple bucks and go with MR43TS AC/Delcos... extended tip plugs.

Thanks

Will;)