Unfortunately a remanufactured Roch B doesn't guarantee that it's a good serviceable carb. I purchased one in hopes it would work on my newly rebuilt 235 as the carb that came with the engine had several issue also. The reman carb had worn throttle shaft bosses and caused a hard to find vacuum leak. Sent it back and he sent it back to me no trouble found.
You should easily see the accelerator pump squirt fuel down the throat of the carb when it's working properly. Since it idles good the assumption is it's getting fuel.
One thing I found out in working on these B's is the fuel bowl has to be nearly full in order for the pump to work on some models. The pump well gets it's fuel via overflowing into the well. Some others use a fill passage and check ball to fill the pump chamber. There's a possibility the float may not be adjusted properly as well as what Joe mentioned above.
My caution about opening up the Roch B was to try not to disturb a non-leaking carb. But it seems you've isolated the trouble to the carb.
Good luck
Dave
