View Full Version : Xb9r RevPerf big bore kit

11-08-2014, 04:03 PM
Hey guys. Kind of a newbie here on buellxb as this is my first post. I just turned 19 and I've got a 2003 xb9r that's got about 30,000 miles on it now. I've done a few things to it:
K&n filter
D&d exhaust
Breather re route
LSL steering dampener

But I'm ready to get into some more in depth mods to really bring out the most of this bike. I'm considering going with RevPerfs 1170cc big bore kit and I plan on getting the heads ported and polished and I was wondering what all I should do with this. Would case boring be necessary? Should I upgrade any other parts when I decide to do this? (Camshaft, piston rods, etc)? Sorry Ive never built a motor before but I am going to college for Motorsports engineering so I figured I'd start with my buell! Any input would be much appreciated! Thanks in advance!


11-08-2014, 08:43 PM
RevPerf is quite pricey...look into Hammer Performance instead. They have a 1200 kit for the xb9 short stroke. Yes, it does require case boring and that requires tearing the motor completely apart. Most people would argue to just buy an xb12 motor and swap it out for the cost. Now a lot of people with xb9's go with a 1050 kit with does NOT require case boring. Of course getting the heads done really helps, I just had mine done...1.9" intake valves vs 1.8" stock, 1.615" exhaust valves vs 1.5" stock. Heads are milled .020" to get compression up. My cylinders and pistons are still oem 984cc, but I had to rework the valve pockets on the intake side of the pistons to get piston to valve clearances. With my squish at about .030" I'm right around 10.5-10.8:1 compression. I also run Redshift 567 cams. And with many cam selections you need to have the heads prepped to work with the cams you use. I've got Jim's Poweglide II hydraulic lifters, and .050" shorter chromoly push rods to support the valve spring pressure and adjusted for different cam base circle diameter and head decking. I've also got XB12 Throttle body and header on my xb9. Requires a complete retune...but the power is definitely there.

11-08-2014, 08:48 PM
Oh...and typically you don't really need to replace connecting rods unless you plan to spin the motor 8k rpm or higher...at that point you really should be having the crank pin plugged and welded and a full dynamic balance of the bottom end. That's probably close to $1200 alone. If you feel your crank needs to be done, a standard rebuild with balancing is like $500. But as long as you don't have excessive play on the crank journal, then you're okay.

11-08-2014, 10:16 PM
Gotcha. That was all the info I was looking for. I was looking into nrha, hammer, and Revolution. So you'd recommend going with hammers 1050? I want to upgrade the displacement but I don't want to sacrifice the shorter stroke of the xb9 cause I like how it revs higher. I'm not too knowledgeable on this as I'm just now getting started with motorcycle engine theory and stuff. I figured I'd get advice from the best. You guys are like Gods among men haha. I really appreciate the input man. thanks a ton!

11-08-2014, 10:54 PM
It all depends on how much $$$ you are willing to spend...it's real easy to drop $4000 in a motor. I'm $2k just in head work, cams, lifters, and push rods

11-08-2014, 11:48 PM
Well I'm willing to spend probably around 4000 on it. It won't be for a little bit as there are other things I need to get to first (previous owner wasn't too great with maintenance) and I was originally considering selling it to get an 1125r but I just love it too much haha. In what order would you suggest doing motor work? I was gonna go with the upgrade in displacement and getting the heads ported and polished first.

11-09-2014, 02:48 AM
Consider some brake and suspension upgrades as well as engine mods. The $$$ add up fast!

11-09-2014, 04:34 AM
@SpeedyG I was already considering ordering the new ebr rotor and finding an 1125r master cylinder and 8 piston ZTL. If I don't end up selling the xb9 for an xb12 or 1125, It'll get all kinds of goodies haha. [up]:)

11-09-2014, 10:18 PM
The only thing...if you plan on putting cams in the bike, the heads need to be done to support the cams you choose. If you stay with stock, than a big bore and heads is pretty straight forward.

11-10-2014, 03:10 PM
it's real easy to drop $4000 in a motor.
You can double that done right.

11-11-2014, 03:09 AM
Thanks for the help guys, because of it, I think I've decided to upgrade to either an 1125r or xb12r when summer comes around and then start messing with the motor

11-11-2014, 04:34 AM
Summer is for riding! do your mods in the winter so you don't have any down time

11-11-2014, 12:30 PM
I think I've decided to upgrade to either an 1125r or xb12r
WHY? Two entirely different engines as far as power delivery.

but I don't want to sacrifice the shorter stroke of the xb9 cause I like how it revs higher.
THIS is what makes it FUN in the twisties.
An 1125R would be a nice 'upgrade', but I wouldn't swap a '9' for a '12'....especially after your comment. THAT single point is what makes a 9 fun to ride. Some guys don't care about that...they never turn it past 5-6K RPM anyways and that's cool. But...it sounds like your riding style and enjoyment dictates the personality of a '9'. You could have a lot of fun with just the 'smaller' big-bore kit, get Hammer to do your heads, (DON'T try to 'port and polish' these yourself unless you have LOTS of experience with porting and a flow-bench. You will probably hurt more than help otherwise), and a nice set of cams. (Remember...the short stroke requires different camming than the 12's due to the crazy rod/stroke ratio....that piston hangs at TDC/BDC a LONG time!), a KEDA exhaust, (his smaller 1.75" primaries), and you're set! One of Erik Buells' favorite personal rides is a big-bore '9'.....I think that almost speaks volumes right there! ;)

11-11-2014, 04:02 PM
Consider some brake and suspension upgrades as well as engine mods.
What he has already exceeds the needs/requirements of most riders....especially in the suspension department. Keep the forks in good shape, (Good/proper weight fluid, seals, etc.) and you're golden. Set them, as well as your rear shock, up to what the book specs for your weight, then make SMALL tweaks and ride it for a bit, (NOT just around the block), get a 'feel' for it and go from there.