Spark plug gap

[noah4009]

I have a 1971 55HP Chrysler. My manual calls for a L4J. I went on Champion site and it crossed to L82C which I used and works fine. It also says in Chrysler manual gap is .030 but in Champion site for marine plug L82C it says gap is .040 I set at .030 and that works fine. Is .030 correct or should I gap at .040 as Champion says?

 

[john from md]

Re: Spark plug gap

If the Chrysler book called for .030 then the dwell and coil were spec'd out to give you the right spark at that gap.
If the engine is running smooth and not too rich, leave it alone. It takes a stronger spark to jump the larger gap and your engine isn't any spring chicken.

The Champion plug is obviously a later model and ignition systems are more powerfull then they were in the '70s.

Regards,

John

 

[noah4009]

Re: Spark plug gap

Thanks John