View Full Version : XB12R to 88ci.

03-21-2019, 05:59 PM

I have a 2004 XB12R and I've been dreaming about 88ci big bore kit.

Can anyone tell me reasons, why I shouldn't do it? Does anyone have 88 kit in XB12?

If I decide (read: get money) to start this kind of project, what else should I change?

Thanks for answers and sorry, if my writing is hard to understand. I'm from scandinavia and my school years are far behind. 😁

03-21-2019, 06:35 PM
Your English is fine. I'm not at the level of expertise as some are on this website, but in my opinion the XB models have about as much horsepower and torque squeezed out of them as possible while still maintaining longevity and reliability. Unless maybe you're into drag racing it or something.

03-21-2019, 08:34 PM
If its your dream and money is not a barrier, go for it. Don't be surprised if the cost of the conversion, including tuning and all the extra parts is more than double what the bike is worth.

If you want a fast Buell on the cheap, get an 1125R. It will run circles around your 88ci Firebolt.

03-21-2019, 11:50 PM
Tuning will be your only issue
Not much info out there on tuning big bore Buell(2003 and up models).

If you do decide to mod... highly recommend converting to a 2008(or above) crank bearing and crank set up. 2004 to 2007 models have been known to have crank bearing issues. Some will protest that its not a known issue, however, I have experienced this failure. I also firmly believe the manufacturer would not arbitrarily convert bikes to a larger crank set up.

Cost wise, you’re looking at about 3-4 thousand dollars(US), not sure of the conversion. I say that much because it would be pointless to do a big bore without modifying the heads, cams, fuel regular and fuel injectors.