| Author | Message | ||
     Mtdan |
Sparkplug recommendations: Uly '06 shop manual 10R12(A), in the '09 manual 10R12X....what's the difference. I now have an '09. Also tried to find NGK DCPR9X locally but no shops or autoparts have them (auto parts don't even have a reference for them). Local harley dealer has the 10R12(A), but not the X....closest Buell dealer is 150 miles from me. Any insights would be appreciated. Thanks. | ||
| Paul56 |
Not sure about the "x", but I ran the Harley 10R12APP (double platinum) for about 80k miles without any problems (2 sets in that time- yes, I know it's more than the recommended mileage). Most recently, at 100k, I switched to the Iridium NGK's from American Sportbike, just for a change. | ||
| Dr_greg |
I've used 10R12A plugs for many tens of thousands of miles on my two '06 Ulys. I do change at recommended intervals. Never had any kind of problem. --Doc | ||
| Pontlee77 |
I'd go for the iridium, i noticed a reasonable increase of power on the bike, some don't notice it, i did, and they are supposed to last longer. | ||
| Mark_weiss |
10R12X is a foul resistant plug that was first spec'd for the '08 model year. | ||
| Ratbuell |
DO NOT use X plugs in an 06/07. It is only to be used in 08-up bikes. It is an anti-fouling design (different heat range) for the later DDFI-3 bikes. 10R12A is still the correct plug for 06/07 bikes. | ||
| Al_lighton |
Joe, Where did you get that info? I was told the opposite by someone at Buell that I trust knows this stuff. He told me that the X is the same heat range but has a different insulator design that is more foul resistant. Al | ||
| Zac4mac |
I ran the 10R12A in my Uly for 10k miles. The tech that did the 10k service was a moron and screwed up a couple of other things I found when I did the 20k. No difference in ride when I switched to the "called for" 10R12X plugs. Z | ||
| Mark_weiss |
10R12 designates the spark plug dimensions and heat range. Both are the same in those matters. The final letter designates the tip design. A is standard, X is a foul resistant design. A quick visual inspection of both plugs reveals that the insulator on the A plug has much more of a taper toward the electrode end than does the X plug. On the A, the insulator is about 4mm in dia. at its end. The X is a about 5.2mm at the end. Both plugs seem to have the same insulator depth (as far as I can measure) and both have the same center electrode diameter (1.98mm). | ||
| Al_lighton |
I found the email from Dan Hurda on this question: "Heat range and gap are the same, the difference is the shape of the ceramic. The shape of the ceramic on the 10R12X burns off carbon deposits better & resists fouling. It was to address an issue we saw primarily at dealers and in our demo fleet; an environment where bikes would repeatedly be fired up cold reved for people to listen to the engine and then shut off without ever getting the plugs warm. They are back compatible to any bike that uses the 10R12 or 10R12A" Al | ||
| Schwara |
If there is no obvious downside to using the X plugs they sound like a good idea. That's more of a question than a statement. Would there be downsides associated with the different shape ... I'm guessing the cost is different, but anything else? I'm always looking for ways to bullet proof the bike a little bit more. | ||
| Ratbuell |
I'll have to dig, but I seem to remember a factory TSB that stated NOT to use the X on the early bikes. I'm quite possibly misinformed about the heat range, though. Sorry. |
