KX Motor
60-65 hp stock
Easily tunable to 80+?? Power Delivery issues?

Higher peak means snappier delivery.
Remember that while it doesn't make much more peak HP stock than a tuned KR1, it has so much more torque its not funny
The Beast I build

:
I'm leaving the motor near stock- got a wiseco Hot Rod and forged piston in it,FMF Gnarly Desert, Digital temp guage and Scitsu tacho. Some piston mods ala stewart off the KXriders forum
Work in Progress
I'll look at putting a Pro Circuit pipe and lectron 44mm carb on it, perhaps raise cylinder slightly so It'll rev easier.
You want to mill a groove in the carb, so that the engine doesn't heat up too much when you shut the throttle at revs and bung the needle back into the hole, stopping the flow of fuel- the groove goes from the main jet orifice to the neck... Towards the motor. Got this one off Dennis Ireland. He had a really cool carb off one of his RG500's
He also reckoned that an EGT was the way to go, so that you can fiddle with your carb settings to work on not having it sieze when you shut the throttle...
Good luck with your beast, and enjoy...
See this site: HEEEEEPs of really useful info...
http://www.kxriders.com/forums/index.php?board=4.0
And in particular, this thread:
http://www.kxriders.com/forums/index.ph ... 839.0.html
These are also interesting:
http://www.kxriders.com/forums/index.ph ... 871.0.html
http://www.kxriders.com/forums/index.ph ... 158.0.html