07 400ex seems weak

[SiK^_^]

alright guys picked up an 07 400ex last year about 7 months ago right before winter hit it probably has about 40-50 hrs on it right now..
went riding today my buddy has an 03 400 ex with just exhaust and a different jet, and i hoped on his just to see the difference and his seems twice as fast he can pop wheelies in 3rd gear no prob and he couldnt do it on mine in 2nd and it seems like his just had twice and much torque and speed when we were hitting jumps he would be in 2nd gear and i had to be in 3rd gear because 2nd seemed like i was about to blow the motor apart....i dont know the most about these but i dont think exhaust and a jet would do that...
can you guys think what could be going on with mine?
and i know he only has a exhaust and jet hes not hiding nothing from me.

[trx400EXtreme]

an exhaust with the correct jets will make that kind of a difference. buy an exhaust, filter, and lose your air box lid and it will seem like a whole new quad. also make sure it is jetted right.

[RaginRedneck]

There was a gearing change in '05, I think. My brother has an '01, I have an '07. When mine was stock he could take me. After a slip-on, K&N, CDI, rejetting and dropping a tooth on the front sprocket, I kill him now.