This is just a word of Thanks to all the people on TT who have posted info on modifications to a TTR250 ur help has made my bike a fire breathing beast. I wanted more power from the asthmatic engine so I spent a couple of days reading the posts on TT. I then spent some time checking out www.ttr250.com. These r the mods i performed on my 2000 TTR250 1.Replaced stock air filter with a Uni filter 2.Drilled 8 holes in top of air box 3. Removed throttle stop screw 4.Cut restrictor out of muffler end of header pipe 5. Installed "Staintune" (Australian exhaust shop) Muffler 6.No jetting needed just followed guide on tuning pilot screw in TT forum 7. Changed gearing from 14/44 to 13/50 8.Pro taper bars and bashplate This is a totally new bike u will not believe the difference this made. Gone from abusing the clutch to raise the front wheel to just lofting it under power. The engine can breath so much better and now builds power in a linear curve right to full wot rather than peaking in midrange then tapering off. The engine sounds less stressed out under load and top speed has stayed the same even with much higher gearing this is due to heaps extra top end power. All in all thanks for the info and anyone with a stock TTR250 do these steps (disclaimer i take no responsibility for results) and ur bike will blow ur mind.