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Spark Plugs

Curious ? Are these all stock engines using the same heat range plugs from Harley? Does it matter if you have a stage one or stage two bike? Wouldn't you change heat range to match your engines lean or rich condition? I'm not trying to start a war , just asking.

Regardless of what brand plug one chooses, one should run the coolest heat range one can run. What one builder might say, another will say different. There is much more to plug reading than pulling the plug and looking at the color of the insulator. First, plug cuts are required for accurate plug reading at cruise and WOT. You get on the bike, get motor to operating temperature and head out with a handful of new plugs and new plugs in the motor. If checking at WOT or cruise, kill the motor under the condition for which you are checking, pull the plug and read the ground strap for heat range and the base ring for jetting.

The ground strap indicates the heat-range of the spark plug. If the "color" of the ground strap "changes" too close to the ground strap's end, (which is above the center electrode), then the heat-range is "too cold" , meaning that the strap is loosing heat too quickly to the base ring, and is not able to burn off deposits until near its end. If the "color" of the strap changes near where it is welded/attached to the base ring (last thread ring), then it means that the plug heat-range is "too hot", because heat is not being transferred/cooled from the strap to the base ring quickly enough. The strap might begin to act like a "glow-plug", eventually causing pre-ignition and/or detonation later on. Proper heat-range is when the "color" is at the half-way point on the strap, neither too cold or too hot.

Check the plug you are running for heat range; you might be surprised.:shock
 
Back in the old days we ran different heat range in front and back cylinders, with modern fuels and injection there is no advantage IMO unless you are drag racing only
Boy does that bring back some memories Jack. Plus, the hotter plug made it easier when you brought it up on the front cylinder for a kick start.
 
Back in the old days we ran different heat range in front and back cylinders, with modern fuels and injection there is no advantage IMO unless you are drag racing only

Very good point, we're talking about a naturally aspirated gas engine either carbureted or injected and a onboard computer making the necessary adjustments. Not like the good old days when ya threw in whatever you had on the bench.

IMO a stock plug (whatever brand you choose) will serve you well unless your running a pretty radical build.
 
All my builds on the TC Before my 96" to 103" were Happy with the 6R12's...

Now needing a little cooler plug with my Higher compression Build on the 103", I am using the SE black top plug... Not the colder one for High Compression, Just the standard 32192-10 gaped at .035 Sceamin'Eagle plug... I was told by my HD Tech: It IS one step cooler than the 6R12's...

I do like the way they run in my 103" using that Fine Wire center electrode, built to be very Compatible with my SE off road tuner.
(yes, I do run my bike "OFF ROAD" Only with That tuner....... LOL)

signed....BUBBIE
 
All my builds on the TC Before my 96" to 103" were Happy with the 6R12's...

Now needing a little cooler plug with my Higher compression Build on the 103", I am using the SE black top plug... Not the colder one for High Compression, Just the standard 32192-10 gaped at .035 Sceamin'Eagle plug... I was told by my HD Tech: It IS one step cooler than the 6R12's...

I do like the way they run in my 103" using that Fine Wire center electrode, built to be very Compatible with my SE off road tuner.
(yes, I do run my bike "OFF ROAD" Only with That tuner....... LOL)

signed....BUBBIE

Ok Bubbie, I wanna see pic's of that!:newsmile100:
 
All this talk of spark plugs lately made me figure it was time to change out my plugs. 17K on original set of 6R12's. Went to the dealer and he convinced me to use the 6R12G, which is the gold plug. He said it's a little cooler. But now I'm wondering if I should I put these in or return them for the original 6R12??? Or maybe just give them a shot and see if there's any difference??? Any thoughts on the gold plugs for just a basic Stage 1???
Thanks
 
All this talk of spark plugs lately made me figure it was time to change out my plugs. 17K on original set of 6R12's. Went to the dealer and he convinced me to use the 6R12G, which is the gold plug. He said it's a little cooler. But now I'm wondering if I should I put these in or return them for the original 6R12??? Or maybe just give them a shot and see if there's any difference??? Any thoughts on the gold plugs for just a basic Stage 1???
Thanks

**I'd use them....

LOL......IF it is REAL gold and not just **color added, they will work good as Gold improves the sparking ability (lot of Fancy words Not used here) lol..

Along with Emptying the wallet a little more also...:shock

signed....BUBBIE
 
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