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Looking For Colder HD Spark plug

dangerdan

Junior Member
I am running HD 5R6A plugs in front and back cylinder.

I want to run a colder plug in the back.

Does HD make one and what is the model number
 
You can find a number of manufacturers if you cross that plug, but I wouldn't do that. Keep them both the same plug.

Crossed into a champ plug that would be RN12YC for the stock plug. Trying to locate my cross for the champs.

I believe the champ number goes lower for a cooler plug.
 
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I dont want to cross or miss-match plugs.

Just wanted to know if HD made a plug colder than 5R6A. I will talk to my dealer.

Thanks guys
 
Nothing to be gained by going to a colder plug. If you are thinking it will make a difference in the engine temp, it wouldn't be measurable and the engine will not run as good as with the stock plug. Generally the only reason for a colder plug is to eliminate a pinging problem from other problems.
 
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