Originally Posted by Zahnarzt
I haven't heard of fitting 250 carbs.
What model/size will work?
i'm not sure what they were called over there. over here we have ZZ-R and GPX 250s. mine came from a '95 i think. they are 30mm. up from the 26mm stockers. being keihin carbs, all the tuning stuff is available. they were a definite performance and economy improvement for me.
i still need some bigger idle jets and had to drill the mains a bit. on a stock TT600 the jetting would probably be very close.
my bike has a 19L Acerbis tank on it. it has a bit more room around the carbs than the stocker. it still required some reshaping with a hot air gun. i reckon you could do the same to the stock tank. just go steady and don't get it too hot.
and suspension wise, i used a complete front end from a WR426. it uses the same lower bearing. the stem is about 30mm longer. and uses a different top bearing. i got an adaptor machined to knock into the frame and take the wr's bearing. i also had to add 8mm per side to the steering stops. this worked well for me as it raised the handle bars. ( i'm 6'2" )
one other bonus with the WR stuff is it came with a speedo drive. the WR cable works with my speedo and is surprisingly accurate. i was surprised when the stock fork springs ended up being pretty good for me. the brakes are heaps better too.