Which Champion J6C for 1964 3hp Evinrude Yachtwin

[LargemouthBass21]

I looked around the internet and there are multiple J6C plugs out there. Some are very short and stubby, and some are longer and look like normal auto plugs. There are different materials to choose from, like copper or iridium. There are also different applications too...The old plugs that were in the motor when I found it were the longer type and I believe they were also Champion but I cannot remember if they were J6C. Anyway I know I need J6C plugs but which ones do i get? Here is the link straight from the Champion website... https://www.championautoparts.com/Find-My-Part/Part-Number-Results.html?part=J6C

 

[flyingscott]

There is only one J6c sparkplug.

 

[LargemouthBass21]

There is only one J6c sparkplug.

That’s what I thought too, but the link I posted says otherwise? There are many different model numbers for j6c as well...

 

[flyingscott]

https://www.sparkplug-crossreference.com/convert/CHAMP_PN/J6C

 

[LargemouthBass21]

https://www.sparkplug-crossreference.com/convert/CHAMP_PN/J6C

That makes sense, but does that mean there is an error on the Champion website?

 

[F_R]

Just goes to prove that the people that write those charts will recommend anything that fits the hole.

 

[LargemouthBass21]

Just goes to prove that the people that write those charts will recommend anything that fits the hole.

They must have "invented" some more in order to fool people into buying?

 

[F_R]

A real J6C spark plug:

https://www.iboats.com/shop/brp-spark-plg-j6c.html

 

[Vic.S]

I looked around the internet and there are multiple J6C plugs out there. Some are very short and stubby, and some are longer and look like normal auto plugs. There are different materials to choose from, like copper or iridium. There are also different applications too...The old plugs that were in the motor when I found it were the longer type and I believe they were also Champion but I cannot remember if they were J6C. Anyway I know I need J6C plugs but which ones do i get? Here is the link straight from the Champion website... https://www.championautoparts.com/Find-My-Part/Part-Number-Results.html?part=J6C

The first one on the list J6C part number 823 .

All the others are discontinued / obsolete part numbers !

 

[LargemouthBass21]

The first one on the list J6C part number 823 .

All the others are discontinued / obsolete part numbers !

Thanks!

 

[racerone]

A CJ6 is not the same as a J6C

 

[oldboat1]

'64 manual lists J6 rather than J4? I use J4s in my 3s, with a 24:1 fuel ratio (mid-'50s to early '60s).

 

[LargemouthBass21]

'64 manual lists J6 rather than J4? I use J4s in my 3s, with a 24:1 fuel ratio (mid-'50s to early '60s).

That’s what I’ve read

 

[LargemouthBass21]

A CJ6 is not the same as a J6C

That is correct, a ‘64 Yachtwin uses J6C plugs

 

[racerone]

Long ago ( 1970 BC ) where BC means BEFORE COMPUTORS the rule was J4J with thermostat and J6J for motors without a thermostat.------It seems it was easy back then.

 

[LargemouthBass21]

Long ago ( 1970 BC ) where BC means BEFORE COMPUTORS the rule was J4J with thermostat and J6J for motors without a thermostat.------It seems it was easy back then.

Everything was simpler. I can work on this motor easily and understand how everything works. (Except how to clean the water passages but that’s for another day)