Some boring photos of a Yamaha WR200 carb. Normally this work should be done on a 4-jaw independent chuck. I've used shims and took the carb countless times out of the chuck as to achieve the smallest runout. Then I bored the carb from 29.2mm to 31mm. Normally, the carburetor should be offset as well, as to remove the smallest amount from the base that the carb slide fits.