Ok I put on a yoshi pipe and rejetted. rode for about 2 months and the intake valves or seats recedded and caused the cam to hold them open thus it wouldnt crank after cooling down. I reset clearance and down jetted sinch the plug looked black. Rode for 2 months and same problem. Took my head off and went to my dealer. He said he'd never seen the problem and didnt know what was causing it. The plug was still black. it also started smoking blue after the first adjustment. I looked at the cylinder and it looks great so I think it was slipping oil past the valves but not sure. The choke stuck closed one time before and was fixed. Plan on rejetting once head is sone. has anyone else had problem with choke sticking open and causing rich condition? any help or advice would be greatly apprecatied Thanks.

 

I had my choke stick on an 05 Z, took it to dealer they got it unstuck, I installed hand choke and got rid of the crappy factory cable set up. It cost me a days ride. No more problems as of now.