surface fire vs regular spark plugs

[jamescody]

what are the advantages of a surface fire spark plug...they are the factory recommended plug for my 90 hp mariner, but I'm not to sure I like them. For starters, they are hard to read, secondly, just the design of the plug makes it look like it would foul much easier than a regular electrode plug. The only positive I can see is that they are a longer running plug due to the fact that the spark has a 360 degree area in which it can jump.<br /><br />Is there anybody out there who changed to a regular type plug, and if so, what was the outcome?<br /><br />Thanks<br /><br />James

 

[wilde1j]

Re: surface fire vs regular spark plugs

I've run both surface gap and conventional Champs in my '85 J 140. Manual claims conventional plug does better in sustained low speed (non-planing) operation, but I haven't noticed much difference. My low speed operation is often fast sw trolling (i.e > 2000 RPM). The only real difference is the surface gap plugs last several seasons vs one for conventional gapped plugs. Basically, no significant difference (top end same, acceleration same, fuel economy same, etc.)