Spark Plugs

usma41 · Post by **usma41** » Sat Dec 09, 2006 4:20 pm

Is it safe to put ChampionXMJ-17 in the M38?

Post by **wesk** » Sat Dec 09, 2006 8:46 pm

The correct plug choices for the M38 are XMJ-14, WR44, AR5S, 243 or MS35909-1.

The correct choices for the M38A1 are XMJ-17, WR46, AR7S, 2245, or MS35909-2.

You'll notice all the A1 plugs are one or more heat range numbers higher than the M38. In average conditions you can get by with the hotter plugs in the M38 and if she's burning a little oil and starting to foul plugs on you it's a temporary solution.

Cacti_Ken · Post by **Cacti_Ken** » Sun Dec 10, 2006 10:33 am

What makes one spark plug hotter than another?, Is it a resistor in the plug?

Ken

Post by **wesk** » Sun Dec 10, 2006 4:19 pm

Varies with manufacturer but it is usually the length or positioning of the center electrode nose which determines how far the cooling path is.