Tried out the oko tonight to try and get it right with the jets to hand, i reduced the slow jet to 40,this seems right off the bottom but the front end lift is chalk n cheese compared to the TK def more power/responsive with the oko, I prefer the TK though off the bottom, i cant get the middle-top end rev out right with the OKO, I will have to get a 135M tried a 130M no good,Ii feel the needle may need changing hope not... I think slack may have the answers to this problem....I like messing with bikes though :-0

I think I have sorted this now with the help of slack...I checked my piston in barrel with rleation to ports  etc, its position seems fine, there are several wossner pistons that will fit this bike and also several conrods......however the guy that rebuilt this bike seems to of got it right...the problem(remember im new to these bikes), was a missing gasket on reed intake(cheers Slack), but the biggest problem was the carb(slack pointed me to this also), all this crap had appeared from somewhere in the float bowl(i first looked at it to begin with when  this problem started a few weeks ago and looked clean/spotless,) anyhow move on a couple of weeks.....so I stripped TK carb out yesterday proved every gallery was clear, then cleaned it and all components in ultrasonic cleaner checked float height, I also put new fuel piping on and inline filter(cleaned fuel tank and clean fuel were done a couple fo weeks ago). left it over night. come to start it with choke FIRST KICK :-) ,left it for a few hours same again first kick from cold and first kick when hot sorted, weyhey........just gotta ride it now ??

I have a 3rd os Yamaha piston , if you need info.

Guy