Shim the cush drive. Here is Alex's info that I used to do mine (Thank's Alex!)
http://www.ninjette.org/forums/showp...2&postcount=20
And let me tell you, it makes a world of difference! Also, get the front forks under control. Depending on your body weight the stock springs and oil are worthless, almost dangerous. For me at 250-260 geared-up the stock fork compressed so badly as to make the rear brake useless. If you want the $15 method or the $130 method let me know and I can tell you what I did.