Before buying a new spark plug, I Googled to find which one to use on a 1980 2hp Johnson Seahorse, model J2RCSM, problem is I get different numbers coming up, so how do I know which one is the right one or the best one , and why is it best?, Most say use Champion or NGK, but the numbers vary from a Champion J4C, J4J, J6J, J6C, RJ6C, or NGK, B6S, BR6S, B6HS, of course there are others, but those seem to be the most frequent. MarineEngine.com says they recommend a Champion J6J, but the Champion plugs they list for sale is a J6C,or a RJ6C, so I don't know what to believe! all I know about spark plugs is some have shorter thread than others, Does anyone know what number they came with when new, should I stick with that or go with something different, and why?. Very complicated decision for such a small item, but don't want to do damage by using wrong one, the one in it when I got it was an old NGK BS6, which may/may not be why its hard to start and runs rough. Any help is appreciated, Thanks
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