Spark plug question

[MWENGER1]

Hi,
Can anyone tell me the difference between a Champion Spark Plug L77J4 and L77JC4. Thanks in advance for your help.

 

[JB]

Re: Spark plug question

I think this will get better response in Non-Repair Outboard, MW.

I will move it there.

 

[gcboat]

Re: Spark plug question

The L77JC4 is a replacement. The important part is the "77" which denotes heat range.

 

[MWENGER1]

Re: Spark plug question

Thanks for the info gcboat.

Thank you also JB for moving my question. I did not see this forum.

Thanks to both, MW

 

[seahorse5]

Re: Spark plug question

Hi,
Can anyone tell me the difference between a Champion Spark Plug L77J4 and L77JC4. Thanks in advance for your help.

The C at the end denotes a copper alloy core

The 4 means that the factory gapped them at .040"