big bore

[bcguide]

Ok it time I Drug my old bike out of the shed and rebuilt it
So what is the best big bore kit. Will an xjr cylinders work?
Do any of you have an lightlybused parts around

Scott

[Pat Conlon]

Hey Scott.  Yup, buy one of these:
http://cgi.ebay.com/ebaymotors/Legends-Race-Car-600-INEX-FJ1100-FJ1200-XJR1250-/180490850307?pt=Motorcycles_Parts_Accessories&hash=item2a0617d003

According to Curt Andrews, the Legends guys take these oem 1250 blocks off their new XJR motors because they need sleeved blocks for durability i.e. the Nikasil chromed bores go out of round with the WFO 10k rpm racing these guys do, night after night.
However, these blocks are just fine for street motorcycles, and in some ways superior.
Along with the added power from the bump in displacement, the Nikasil plated cylinder walls of the 1250 block sheds (transfers) heat better and has less friction than our sleeved blocks. Curt mentioned to me that he took a sleeved 1250cc motor dyno'ed it, then, using the same motor, installed a XJR1250 block with plated bores, and put it back on the dyno, and gained 9 hp.

Get some 79mm pistons of your choice, and some nifty XJR rods...You will have to have your oem case relieved to fit the XJR1250 block. No biggie.

Want Even More Power?
To further bump the displacement from 1250cc to 1350cc several folks bore out the XJR1250 block, install sleeves, and run 82mm pistons.

Have fun and bring your wallet....

Cheers!

[bcguide]

Thanks

Does the xjr bolt right on other than than milling the cases?

SCott

[racerrad8]

Thanks

Does the xjr bolt right on other than than milling the cases?

SCott

Yes, with the appropriate gaskets.

Randy - RPM

[fj1250]

I've got a cylinder with 1202cc pistons, very good condition.
Hone, re-ring and drop it right on.
$175 + shipping.
Mike C

[fj1250]

I'm going to have a set of 1250cc pistons for sale soon also.

Mike C