| Author | Message | ||
     Boyd |
I just picked up an 04 xb12r with a bad shift fork, so I have to split the cases.. I'm looking for suggestions on engine mods to do while the bike is apart. I'd like to add some power without losing much on the reliability side.. Any ideas would be appreciated! | ||
| M1combat |
2008 Crank + conrods. 2006+ oil pump drive gear. After that... I went with a small bump in compression (10.6-8 I think) and some head porting. If you can't do the heads yourself or know someone then just tune the thing. Some people have made over 100 at the wheel with just exhaust and tuning. | ||
| Greg_e |
XB9 pistons to raise the compression ratio, exhaust, tuning is your least expensive route. Big bore kit would be next with the same exhaust and tuning. Head work will give you a little bit more and then you would want to go with a larger throttle body and maybe bump the fuel pressure regulator to the higher pressure racing device. You could put in a small amount of nitrous, done in small enough amounts it will still give decent power, and be less likely to fry the motor. | ||
| Teeps |
Boyd Posted on Sunday, January 20, 201 I'd like to add some power without losing much on the reliability side.. If I had a bottomless supply of money, I would install a 2008,9 or 10 engine and electronic controls. And this BOLT-ON 1250 Kit: http://hammerperf.com/xlbigborekits.shtml#1250kits and call it good. | ||
| Greg_e |
No an endless supply of money would be bore the case and put in a bigger bore kit, heads, TB, exhaust, new ECM with professional racing company tune, etc. Essentially the XBRR recreated. If I was doing it I would swap to the short stroke crank (XB9), big bore kit (maybe bigger bore kit with case machining) and look into having some head work done. But that's going to be about $3000 in parts/labor before you even start putting pieces back together. If you decide the cylinders need work beyond a simple hone then you are at the bolt on big bore stage since this is only a little more expensive than stock cylinders and pistons. For me my 1050cc (xb9 crank) kit is plenty of power, since the stock 1200 makes a little more I don't think I would care for additional power. Alternate to all this you might want to put the XB9 primary chain/sprockets on your 12 engine, this would give you a bit of low speed grunt and several people have done this and like it. It is by far the cheapest way to get going faster from a stop, but you lose the maximum speed. Chain drive conversion might also be worth looking at so you can change the ratio to fit your riding style, but not exactly cheap unless you find a used one. | ||
| Slaughter |
Hint: ALL motorcycles are geared way too tall for road racing. No exceptions. | ||
| Ducbsa |
Maybe the Isle of Man TT would be an exception? | ||
| Reepicheep |
Only when the corner workers are out. Which reminds me, I have an XB9 primary sitting out in the garage waiting to go into the uly!  | ||
| Portero72 |
Do it, Reep. It rules. Had it on my Uly for 20k and would never go back. |
