"It's the carburetor" is the last retreat of an incompetent mechanic. A carburetor is nothing but a chunk of metal with a bunch of precision-drilled holes in it- - - -there's not a whole lot that can go wrong with it. If the throttle shaft bores aren't worn to the point that it's leaking a lot of air around the venturi, and the carb is correct for the engine it's on, your problem is most likely somewhere else. That being said, "Rochester" might be the problem- - - -"Carter" would be better! When Chevy began building their own carbs in the late 1940's instead of buying their carbs from Carter, the CEO of Carter vowed to sell a million replacement carburetors for Chevy engines. It took several years to accomplish that goal, but the 1-millionth Carter replacement for the Rochester got gold-plated and presented to the CEO of GM! Their slogan back then was "The ABC's of carburetion are 'Always Buy Carter'!"
Jerry
