Hey everybody!

I rebuilt my BBS and used it long enough to realize it needs more work. The motor won't idle very well below 700 rpm. It was also leaking fuel pretty badly. Spraying carb cleaner around the unit indicated air leaks around the choke and throttle shafts.



What is the diameter of the shafts and their bores?

I measured the choke shaft at .249, throttle at .309, and both bores are .010-.020 over those measurements. The throttle shaft is nearly the same measurement all over the shaft, so it either wore VERY evenly or none at all. I ordered some bushings from McMaster Carr this afternoon (Sooo cheap!), and a couple proper sized shafts. That way, if the original shafts are still too small for the bores I can cut new ones.



Should there be O-rings on the throttle shaft?

While conversing with a motorcycle mechanic, he stated that the grooves on either end of the throttle shaft needed o-rings. I haven't read anything about that, but it makes sense, since the bores are so much larger than the shafts.



How can I safely straighten out the top plate? A little heat and hammers? 10-ton press?

I understand that the carb body and top plate warp together over time. Mine mostly does, but the bow on the front side Top and body is too dissimilar and it leaks fuel inside and out. I might be able to just bend the mounting ears on the top a little to get it a little bit flatter and sealing properly.