I am at a complete loss as to what's going on with my bike. 1971 Cb350. Started for the first time in many years last weekend. Ran fine for the first 20 miles or so (except for a clogged petcock, easy fix) and then on my way to work Tuesday it started to miss, backfire, run like junk. I did find rust in the tank, fuel filters, and carbs. Since then I have changed to a clean gas tank, new fuel lines, fuel filters, and cleaned the carbs with no improvement. I then changed the carbs to another set with again, same symptoms. I swapped the coils, no change. I swapped the condensor, no change. I have no idea what to do next. left cylinder runs fine. right cylinder seems to idle I think (the pipe gets hot right away) but when you open the throttle it stumbles and backfires like crazy. I've opened each throttle independently and the left cylinder runs through the RPMs smooth as can be. The right cylinder will increase a little, but starts to stutter and backfire. Is anyone around the Cleveland area? I would glady pay for someone with more knowledge to at least point me in the right direction at this point.