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Old Jan 30, 2017 | 03:21 PM
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Default spark plug gap
My owners manual states that a H-D 6R12 spark plug is to be used with an 2003 RKC. The gap is from 0.038 - 0.043. Why such a variance in gap? What is the spot on gap? I know with my 1965 sportster with points, plug gap had to be closer than that.

Randy
 
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Old Jan 30, 2017 | 05:24 PM
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Because if you are in that range it don't madder.
 
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Old Jan 30, 2017 | 05:26 PM
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The difference in gap is only .005. that isn't very much. I like to set plugs on the low side to account for erosion of the ground strap and electrode.
 
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Old Jan 30, 2017 | 06:05 PM
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Set it to .040 and forget about it.
 
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Old Jan 30, 2017 | 07:44 PM
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I've used the .040" forever (since '99), works all day long.
 
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Old Jan 30, 2017 | 07:52 PM
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Originally Posted by slhanks4
Set it to .040 and forget about it.
Originally Posted by seniorsuperglideE8
I've used the .040" forever (since '99), works all day long.
This, the range you read about is minimum/maximum. Split it at .040" and ride.
 
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