[jonathan180iq]

I can't figure it out. I get the same mileage as always but, as you mentioned, can't break 60MPH at full throttle and I'm a lightweight. My buddy can shoot 80 with a 15T sprocket and he's a middle/heavy weight.

That being said, I get better mileage than he does.

I would guess that it has to do factory jetting and location. However, with the two bikes I am familiar with, they were purchased at the same store 2 months apart and we live in the same town. I don't know if they came from the same facotry.