I came across this cheap and simple way to derestrict the KLX/Tracker 250 on www.svendura.de - no idea if it works but since it's so easy it's worth to try it out! It's a German website so if you read German you can follow the instructions there. First picture: locate the plug close to the clutch lever. Pull out the plug and bridge it - bingo! This supposedly activates a second, hidden ECU map and lets the engine rev all the way in all gears. A wire of appr 1.5mm strength should do the trick. That's the idea! Job done! And it's easy to reverse without anybody ever knowing it, so no worries about voiding the warranty. Now tape it/secure the cable to the handlebar and make sure the wire stays in. I have no idea if this works - it's almost too easy to be true - so if someone tries it out, please post the result!