Correct Spark Plug for a 1980 Johnson 2hp

[ali'i]

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, 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. 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 B6HS, which compared to other plugs, seems to have a rather long threaded part which may/may not be why its hard to start and runs rough. Any help is appreciated, Thanks

 

[Vic.S]

Re: Correct Spark Plug for a 1980 Johnson 2hp

The original plugs would have been Champion J6J or XJ6J , now both obsolete, or AC M44C.

The latest recommendation is Champion RJ6C gapped at 0.030" ( Resistor suppression and Copper cored)

If you use NGK then the nearest equivalent is BR6S. B6S is the same without the resistor.

Check how good your spark is if you have difficulty with a new plug.

 

[ali'i]

Re: Correct Spark Plug for a 1980 Johnson 2hp

The original plugs would have been Champion J6J or XJ6J ,or AC M44C. I think now all obsolete types.

The latest recommendation is Champion RJ6C gapped at 0.030" ( Resistor suppression and Copper cored)

If you use NGK then the nearest equivalent is BR6S. B6S is the same without the resistor.

Check how good your spark is if you have difficulty with a new plug.

What does the resistor do??, and what, if any, is the advantage to buying, say a Champion RJ6C over a J6C, or an NGK BR6S over a B6S, also, I have a new NGK B6HS, could it work? without damage being done.? Thanks

 

[ali'i]

Re: Correct Spark Plug for a 1980 Johnson 2hp

To those that may have read my original post earlier, Please note I made a correction to my original post, I had gotten the plug that was in the motor mixed up with another one I had laying around. The plug in the motor was an old NGK B6HS, with a long threaded part,

 

[Vic.S]

Re: Correct Spark Plug for a 1980 Johnson 2hp

What does the resistor do??, and what, if any, is the advantage to buying, say a Champion RJ6C over a J6C, or an NGK BR6S over a B6S, also, I have a new NGK B6HS, could it work? without damage being done.? Thanks

To those that may have read my original post earlier, Please note I made a correction to my original post, I had gotten the plug that was in the motor mixed up with another one I had laying around. The plug in the motor was an old NGK B6HS, with a long threaded part,

The resistor an interference suppressor.

The recommended plugs and the NGK B6S and BR6S are [SUP]3[/SUP]/[SUB]8[/SUB]" reach plugs. The B6HS and BR6HS are ?" reach plugs. There is a danger that the longer plugs would be struck by the piston.

The recommended plug is now RJ6C. J6C should work equally well

 

[boobie]

Re: Correct Spark Plug for a 1980 Johnson 2hp

Put in a J6C and you should be okay.