This carburetor fit easily without modification. You only need to remove the air box.
 
That happiness in terms of acceleration !
Doesn't fit on injection bikes 
- Keihin PE28 UPower
specialy jetted. It's the PE28 genuine from the Honda CBR150 with a special needle, tube, jets, choke, ilde screw red "UPower"
- Air filter
Uni Filter foam made in USA
- Intake rubber pipe
made in Japan
- front sprocket
with one tooth more to reduce the rpm at same speed that's possible with the extra power