I'm thinking of getting a remanufactured carb to replace my 2bbl Rochester. I just rebuilt mine but I'm getting the same hesitation at tip-in and my plugs seem to show a real lean condition. The throttle shaft is pretty worn which is probably the main problem, plus it's a 78 so it's set lean to begin with. Would getting a reman 2bbl Rochester off ebay that's pre-smog era be set up richer for more power? or is there any good places that rebuild them for more performance?
I had been running my 72 350 with the stock 2barrel setup for a short while, and it had a lean hesitation off the line that I couldnt figure out, and not much top end. No vacuum leaks, no other symptoms....it was puzzling and I chalked it up to an oldish 2 barrel steup. You know, maybe it was weak by nature... When I took the heads apart for my motor rebuild, I found HUGE carbon deposits on the back of my intake valves. I mean it looked like mushroom heads, burnt marshmallows. There was so much stuff stuck there that it was taking up almost all of the intake port. This built up gunk and carbon acts like a sponge and sucks fuel up fast. I believe that it was eating up my accellerator pump charge each time I stomped the gas, thus the hesitation. It also blocked up so much space that I think the airflow was just lousy, and so the crappy top end. Im not sayin this is your problem, but its something to consider. Any motor can benefit from a decarbonizing trettment like Seafoam or something. It might be something cheap to try. good luck.
Tin indian performance (look em up on the web) sells a Throttleshaft bushing kit for re-bushing leaky shafts like the one you describe. I think they offer rebuilding services too. I have used their kit and it is easy and definitely works.
Production line rebuilt carbs are a nightmare waiting to happen. You buy a rebuilt carb from a typical parts store, you're buying junk. Carbs rebuilt one-at-a-time by a specialist can be EXCELLENT. I'd be rebuilding the one you have already--unless it's a parts-store disaster already.
I have rebuilt mine but I keep getting bad hesitation just off idle and it seems to be running too lean in general. I'm having a hard time finding any new parts for it like larger jets, I might try some of the modifications I've read about like drilling out the idle feed restrictions larger.
many circle track classes require using the 2bbl. i'd do some research and find out who rebuilds these race carbs and have them tailor a carb to your application. you may find a used race carb on e-bay. buying a reman. is really rolling the dice on the chances of getting a bolt on and go unit. good luck.
