Hey just baught a new fmf 4.0 exhaust for my 2008 ktm sxf 250 and noit sure what i should do if i should bring it in to get it re jeted or save the money and stay like what it is right now. I have been talking to a few mechanics and they all have different opinions some think i wont even need to get my carb re jeted and some do. I got told that if i try the pipe on i could possibly blow the engine, and another mechanic is telling me that i cant possibly blow the engine by trying the pipe on.
Please help me
thank you

Hey guys i dont know if this is normal but if i get into high speeds let go of the throttle then starts shifting down my bike makes like a popping sound is this normal ? a few of my friends bike do this also.
thanks

The first mechanic is an idiot. Never listen to him. You will not 'blow the engine'. Worse case will be you will be down on power and or it will run poorly.
Yes, rejet the bike. Buy a James Dean jet kit. Note exatly what parts you take out and what you put in. Follow the instructions James includes to the letter!!!!!!!!!
Popping is normal on a race bike.

thanks william i ended up buying a jd jetting kit from a local ktm dealer thanks