Help Please

[Jeffmo]

Ok i jus bought an 07 450r a few weeks ago, it always has a bad lag or miss when i hit the throttle, or when barely moving and hit its gotta a real bad lag, well a few days ago i got an HMF slip on, put it on and it was pretty much the same, prolly a little worse. Well today i put the 165 jet that came with the HMF pipe on, and it still lags when i hit the throttle at idle, but now it misses bad at the top end of the gears, anyone have any suggestions?

[TRX450RACER174]

Sounds like you need a leak jet for the lag or bog, as far as the top end miss, is the needle adj on the 07? if not i would say get a HRC needle or another comparable needle and start there, The 165 kinda sounds steep for a slip on pipe w/no other mods, u might need to step that down but i'm not sure maybe some else will chime in that has a little more experience w/ slip on pipes.