| Author | Message | ||
     Dmurphy |
I have a 04 XB12R. I bought NGK DPR9EA-9 plugs to replace the stock Harley plugs. Am I missing something on these NGK plugs? The spark plug cap attachment end seems like it is missing the part to connect into the cap wire. Can someone offer some advice? This has to be an easy deal, as I am sure a lot of people have bought these plugs. See attached pic.  | ||
| Terrys1980 |
Wrong plugs. You need DCPR9E (Message edited by TerryS1980 on August 11, 2011) | ||
| Dmurphy |
Sweet. I guess the knowledge vault title page has to be updated. Thanks for the info. | ||
| Terrys1980 |
I was wrong on my previous post. I have only used the DCPR plugs. There is a screw on piece for the plugs you do have but I don't know where to purchase them from, maybe a local auto parts store. | ||
| Buell_bert |
I have also heard of the new Harley plugs 10R12X which are supposed to have a special coating on the threads so as not to seize and are also less prone to fouling. Otherwise NGK DCPR9E should equal a 10R12 in size and heat range (but with the caps). Yea I bought the DPR9EA's also but had a couple of the caps left from when I had other bikes or snowmobiles. I did have some problems with the NGK's a while back or at least that is what I thought and have stuck with the Harley plugs since. I do use NGK's in about everything else I have. Well good luck. | ||
| Al_lighton |
We buy the caps when we buy the non-iridium NGKs and install them on the plugs before we ship. Al | ||
| Reepicheep |
You don't already have a pile of those caps accumulated over the years in your tool box? You need more two stroke dirt bikes!  | ||
| Buell_bert |
Hey Reep. You got it. I save all the little nuts, screws, etc. and it is usually the little stuff that leaves ya stranded. Well at least if it is close to home you have it, but I live a bit from town and having the small stuff at home saves me a trip. But finding what you need when you want it may be difficult. | ||
| Easttroy |
Are these correct? I assumed they would be since this data's been here awhile, but I've been reading other information in this post. The knowledge vault has this information and if it's wrong, should be updated. At least they are 1.78 a piece and not 50 bucks. Spark Plugs Buell 27661-00Y (10R12) (Supersedes old/hotter 6R12 OEM plugs) NGK DPR7ea-9 hot (not recommended) NGK DPR8EA-9 medium NGK DPR9EA-9 cool (equivalent to Buell 10R12) DCPR same except socket size | ||
| Easttroy |
Answered my own question. NGK DPR* will NOT work unless you have the metal top to screw onto the spark plug. You also run the risk of not having a tool with you to remove the spark plug, since the DPR* plugs are 18mm instead of the 5/8ths that the Harley / DCPR plugs are. Best bet is to use OEM plugs or DCPR equivalent. The knowledge in this vault is not correct as noted by my previous post. | ||
| Harleyelf |
I've been using DCPR8E plugs in my '99 S3 for a year and have had no problems. Starts easy, runs clean, and leaves a nice tan deposit on the electrode. | ||
| Andersonhdj |
Those little screw on should come with the plugs? I'v always bought them so? | ||
| Tango2 |
Looking at this thread because I just replaced plugs in an 04xb12r that I recently bought. The bike has 6000 miles. The plugs I removed are DCPR6E NGK's, so I replaced them with the same. In your estimation is this a problem. Based on this thread it appears that the lower the number, 6 in this case, may be too hot. | ||
| Tpehak |
You have to run the coldest plugs which work without flooding. You can install the coldest plugs people use on Buell and if you experience flooding (engine stalls or start poorly or do not start at all) you can move to the next hotter plugs and so on until the engine will work without flooding the plugs. (Message edited by TPEHAK on May 02, 2020) | ||
| Tango2 |
Thanks for the response. I wonder why someone would have changed to a substantially hotter plug on a low miles, nearly stock bike? The only modification that I am aware of is a jardine muffler. Maybe that was a recommendation with that change? NGK site says a DCPR8E is the factory equivalent. I will probably switch to that since I've read the "too hot causes damage" warning. | ||
| Tango2 |
https://www.ngk.com/NGK-Non-Automotive-Parts-c1419 .aspx | ||
| Tpehak |
If the plug is too hot it will cool down too slow after each stroke and as result it can ignite the air-fuel mixture in the cylinder before the piston passed the top dead center causing engine knocking and it can brake the engine, cause excessive wear and lost of power. If the plug it too cold it will cool down too fast and some fuel and oil stuff will not evaporate and will not burn from the plug surfaces causing plug contamination and lost of spark and engine stall. (Message edited by TPEHAK on May 02, 2020) | ||
| Al_lighton |
The US NGK site has been wrong for years. The UK NGK site is correct. You should be using the DCPR9 heat range, not the DCPR8. A 6 is crazy hot, get it out of there. | ||
| Tango2 |
Thank you both for the additional information!I will be exchanging the 8's then. | ||
| Terrys1980 |
I have a new pair of DPR8EIX-9 plugs I'll sale for cheap. Been sitting around since I sold XB9 a few ears back. NGK part # 2202. | ||
| _buelligan_ |
The reason it probably has that hot of plug in there is from ignorant people thinking its just a sportster engine so they grabbed the equivalent to what comes stock in a Sportster which is the 6R12. I've had plenty of service writers and parts guys try to give Buell customers 6R12 instead of 10R12 just because they didn't know the engine differences nor heat range of plugs. |
