BigBore kit xt660x
 

Hi all!


Me and a friend are wondering the pro's and con's of running a big bore kit.

Does anyone have any experience with this kit? If so;

- Did the bike keep up (maintenance) with the power if i'm not trying to get the last bit of HP out of the setup (like 75+ hp). What maintenance can I expect?

- What bigbore kit are you most satisfied with (what piston, throttlebody)

I'd like to get more torque on the lower and mid range of the bike, so yes or no on the OTR race camshaft.

Thanks!
- Bacon

I seem to remember that you will need to machine the crankcases to accept the larger barrel sleeve. It might not be quite as simple as just fitting a barrel and piston plus cam. There's also the question of fitting larger valves and machining to fit.

As for servicing, then I'd guess it's no more or less than normal servicing except you'd have to re-check valve clearances and the basics after the 1st few hundred kilometers.

Also, as you alluded to, there would be an increased fueling requirement which would mean something like a Power Commander and some dyno runs to match it all together with a larger air supply.

Tiz only a guess, but it has been done....Kev's your man, ask him directly if you have subscribed to the forum.

You don't need to machine the casings unless you go bigger than 103mm, I did machine my casing, I was among the first in the world to build a big bore 660.

I have just about done or been involved in every engine mod on these motors, if you want torque = big bore or bigger bore + stroker crank & standard cam, if you want to move the power up in the rev range the add a high lift cam, the more HP you want you will need to extend the rev limiter in the ECU. The more power put through the motor the clutch will need upgrading.


https://www.xt660.com/showpost.php?p=51632&postcount=59
https://www.xt660.com/showthread.php?t=5895
https://www.xt660.com/showthread.php...ighlight=xt700

Some bits if you want to go big:

CAMSHAFT:HOTCAMS STAGE3 FOR RAPTOR700 or Raptor 5050 cam
VALVES AND SPRINGS:BLACK DIAMOND+2MM RAPTOR7
CYLINDER:105,5MM FOR RAPTOR700
PISTON:JE 105,5 12.5:1 FOR RAPTOR
CRANKSHAFT:HOTRODS +5MM FOR RAPTOR700 CYLINDER TO HEAD STUD KIT FOR RAPTOR 700
FLYWHEEL STARTER CLUTCH GEAR FOR RAPTOR700
STATOR ENGINE MOTOR COIL FOR RAPTOR700
YAMAHA RAPTOR 700 CAM CHAIN
Dynatek Ignition Coil Kit Yamaha FOR Raptor 700
CLUTCH BASKET raptor 700 extra clutch plate
FLYWHEEL IS FROM RAPTOR BUT FLYWHEEL GEAR FROM XT660 ITS HALF.

Awesome! I'm going to read into this.

Thanks for all the info!:glasses2:


-Bacon