Chris Costello
XS650 Enthusiast
The only things I touched when I had the carbs apart were the gaskets and floats. Didn't mess around with the throttle plates.Did you do anything with the throttle plates, like take the small screws out?
Another thought is the nut that holds the throttle actuating arm on the left carb. If you had that off and then tightened her down too much when you reassembled.