Spark Plugs

[Fly Rod]

Could anybody tell me the difference between auto/marine spark plugs besides cost????<br /><br />An answer would be appreciated!!!<br /><br />Thank You!!!!

 

[Rudderman]

Re: Spark Plugs

I didn't know there was such a thing as a "Marine" sparkplug. My yamaha uses the exact same plugs as a honda goldwing motorcycle.

 

[Paul Moir]

Re: Spark Plugs

As far as I can tell, the only difference is that the bodies of marine plugs are made of stainless. I guess that's so they look much better in the trash can when you replace them as part of the spring tuneup. <br />Mabey someone else knows better?

 

[tmcalavy]

Re: Spark Plugs

Well, there are two kinds of spark plugs that I have seen in outboards. One looks just like an auto or motorcycle plug...it has the cuved bar/arm projecting out over the electrode. Most auto/motorcycle plugs I have seen the bar/arm extends/covers the top of the electrode entirely. Not so on marine plugs. The bar/arm stops short so about half the electrode is visible when looking down on it. That's what I know as a outboard plug. The second is a surface gap marine/outboard plug...no electrode bar/arm at all. Just like the ones in my 73 Merc 500 50 hp four cylinder outboard. I don't believe surface gap plugs are used in autos/motorcycles, but I may be wrong...wouldn't be the first time.

 

[Paul Moir]

Re: Spark Plugs

I think FlyBoy is talking about this sort of thing:<br />Premium Marine Plugs<br /><br />Notice how they are equivalant to standard Champion part numbers. For example, Champion 5931 is the same as Champion QL82C, except it's $8.56 rather than $4.25.