Problems with Gold (6R12G)Spark Plugs

[rgonzaleza]

Hi everyone: I have a problem:

I have two bikes: A Street Bob and a Road King Classic, both 2007. They just have installed the Stage One Kit and the ECU flashed by the dealer with Screaming Eagle pipes. (All Harley.) I installed them the Screaming Eagle Spark Plug wires and the Screaming Eagle Triple Platinum Spark Plugs. Both were behaving all right with the exception of some pinging on certain occasions. Because of that I decided to change the Spark Plugs to a more conservative ones, the Harley Gold 6R12G. I calibrated them to 0.040”.

I noticed that the Street Bob got a reduction in the idle RPMS but the engine kept working. The Road King also reduced the idle RPMS but the engine stopped. The engine kept stopping at every red light. I got back to the Triple Platinum Spark Plugs and everything worked OK again. I can’t understand why this is happening. Is this because:
1. I can’t combine the Screaming Eagle Spark Plug wires with (almost) stock spark plugs.
2. The Gold spark plugs does not work all right with my bikes setting.
3. The calibration is wrong.

Why changing a spark plug for another also by Harley can cause such a malfunction?

Thanks for your help and best regards.

Raúl
rgonzaleza@mac.com
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[JCourneyaP]

Either can I. I wouldnt suspect much of a change in any plug you used. At least that noticable. You say it dropped in RPM? How much. You didnt damage the plugs did you? Bad plugs?

Running Bone stock plugs and screaming eagle wires should not kill a motor.

How soon/miles after the dealer installs did you change wires and plugs?
The dealer may have hosed up on the flash.

When you put the old stuff back on is it fine?

[rgonzaleza]

The Street Bob dropped a lot but the engine didn't stop. The Road King dropped enough to stop the engine. After stopping, I re-started and it kept running all right.
The dealer installed the Screaming wires and plugs at the same time and the bikes performed well. The problem began when I installed different plugs, the Harley Gold. I don't think I damaged the plugs. When I put back the Screaming plugs everything worked fine. So, my bike now is all right but it disturbs me that I need to use the Screaming plugs. Perhaps .040" is too opened. Perhaps I should have used the stock and not the Gold. Perhaps I can't use the Screaming wires with stock plugs. Don't know.
Thanks for your help.

[2003FXDX]

How did the plugs look when you pulled them.
Are both sets burning okay or are they lean or rich.

[evoKENevo]

RPM drop in BOTH engines...same MODS in BOTH engines...one DIES...other DOES'NT .. dead (?) one restarts and "kept running all right"...both performed well 'til YOU installed different-plugs...dealer installed plugs replaced...and, all's well AGAIN now !?!

"Hmmmmmm"...040" gap ABOUT-RIGHT for MOST plugs THESE days. Did your issues happen like RIGHT-OFF with YOUR choice of plugs...or SHORTLY there ,after ??? And,like FXDX asks,what did YOUR choice of plugs LOOK like after the fact(s)??? And,what did Dealer-Choice LOOK like,for THAT matter, when YOU took them out (whatever reason) the 1st. time around !?!?

[rgonzaleza]

The RPM drop in the Street Bob and the failure in the Road King began immediately after changing to the Gold sparks. The problem with the Road King was more noticeable after a small trip of aprox 70 miles. When I took out the Screaming plugs after aprox 4,000 miles the ones in the Street Bob looked a little lean and those in the Road King a little rich.
The Gold sparks were too knew to be noticed but I could say that I found the same behavior.

Thanks.

[rgonzaleza]

Hi everybody:

Regarding my problem I will tell you what I did. As I told you, I had calibrated the Gold spark plugs gap to .040”. I decided to measure the gap in the triple platinum plugs that were working well. They were at .036”. So, I closed the gap in the Gold spark plugs and put them on the bike again. Problem solved! I rode some miles and the RPMS were all right and the engine never stopped. Idle was also OK.

Yesterday at night, I was having a coffee with some bikers, and a Harley mechanic arrived. I told him that I had installed Gold spark plugs and that I had had problems. Immediately he guessed that the RPMS had lowered and suggested me to check the spark plugs gap. I told him that I had done it and that it appears that the problem has been solved closing the gap a little bit. He told me that he had had good results with 040” when using high performance wires like Nology, but with stock or screaming eagle wires perhaps a smaller gap could be better, at least for the configuration of my bikes.
I will ride again this weekend an I hope everything keeps going well.

Thank you everybody for your help and ideas.

Regards.

Raúl González
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[JCourneyaP]

Good deal. Thanks for sharing your find. Did the istructions on the "Golds" tell you the correct gap should be .036 or did you just go off the old plugs?

[rgonzaleza]

Hi: I just guessed it. I rode this week end and everything worked ok.

Regards.

Raúl González

[texaswiz]

If you have a late model bike, say 2008 or 2009, then the on board computer will adjust the spark advance in response to engine and riding conditions such as lower octane fuel etc. If your bike came with 6R12 spark plugs it is best not to deviate from those plugs because they come with a special resistor which is used to determine if and when the spark should be altered by the computer. Even if you switch to something like a Champion spark plug, (who makes HD plugs) you will not have the special resistor which only goes in the HD 6R12 plugs. None of the Screaming Eagle plugs have it either.