exhaust question

[350yamaha08]

I have a 2001 warrior..with a full yoshi exhaust and a jet kit..and a k&n air filter...Here is my question this thing hauls butt...has a ton of bottom end power...but it seems to not pull hardly at all in the midrange...and the top about the same....is this normal with stock gearing? 13 40 gearing?....i am confused please help any tips or knowledge would be greatly appreciated!! Thank you :ermm

[350yamaha08]

anyone??????

[scottyyfz450]

i say go into your local shop and buy the biggest back sprocket you can

[Drewltr450]

ok? haha make it a 14 tooth in front try that if that isnt enough take a tooth or 2 away in the back.