i have had some mechanical problems with this bike mostly bad luck kinda stuff ,to long to list. I needed my valves redone so i took it to a shop, Solid Performance,these guy were KTM factory racing mechanics and built the Christini AWD race bikes(CRF250X) so they know their Xs.I got SS valves,2005 R cam,AP mod using a KTM spring sorry i don't have a apart #, Boysen quick shot,and re jetted to Christini specs. My bike is a different bike! It always felt like a trail bike now it feels like a race bike. It has more power everywhere,no bog at all and it's still easy to ride. I was thinking after this season selling it and going on the KTM 2 stroke wagon, So i swapped bikes with my buddy a KTM 200 and rode some great tight trails,I'm keeping my 4 stroke it didn't turn as well as the KTM but it did most things better and easier.