View Full Version : Spark plug gap

11-06-2008, 03:47 PM
"Could anyone tell me how much of a spark plug gap i need. I have a 1986 85hp force.


11-07-2008, 01:58 PM
"anna, i have a '84, 85hp that calls for surface gap plugs.(no electrode to gap) i can't imagine the '86 being that much different (if any at all) to go w/ a completely different plug. that being said, if your motor calls for a surface gap, i wouldn't use a tip plug as it could burn a hole in the piston. so i've heard.."

11-11-2008, 01:00 AM
"Some mfg's will give you two options for plugs.

If you use the motor for primarily "low speed operation" such as trolling, traveling restricted speed zones like canals etc, you can use a "gapped" plug. They just burn better at low rpm than a surface gap.

The surface gap is recommended for primarily "sustained high speed operations".

From factory your particular model would have had a Champion UL-18-V which is a surface gap plug, I do not see a cross listing for a gapped plug."