Champion Spark plug number decoding

97MACHZ

Seaman Apprentice
Joined
Nov 24, 2004
Messages
33
Does anyone know the formula for decoding Champion spark plug numbers/letters. I would like to know the difference between plugs recommended for sustained high speed use and sustained low speed use.<br />Cheers<br />Mike
 

Paul Moir

Admiral
Joined
Nov 5, 2002
Messages
6,847
Re: Champion Spark plug number decoding

Usually it's the heat range. Hotter plug for low speed use to burn off deposits. Too hot and you'll get pre-ignition, which will put holes in yer pistons.<br />
champion.jpg
<br /><br />With Champion plugs, the higher the number, the hotter the plug. Almost all the others work the opposite.
 

97MACHZ

Seaman Apprentice
Joined
Nov 24, 2004
Messages
33
Re: Champion Spark plug number decoding

Thanks very much for the great info.<br />Cheers <br />Mike
 
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