Mikuni vm28 jetting

Why do you want to upsize the carby, what are your mods?
My carb keeps overflowing every now and then. I have cleaned it, set the float, carb kit etc and still acts up. I just figured I would get a new carb and upsize a little. My mods are Toomey pipe, boysen reeds, no lid and k&n filter.
 
No need to get a new carby when all that the one you have now may need is a needle and seat.

The floats may also be sticking, check the float posts for ledges.