It sounds like an accelerator pump problem. Things to look for are a missing check ball that might have gotten lost while the carb was apart for cleaning, worn accel pump piston - did you rebuild the carb with a kit or just clean it and reuse the same parts?, incorrectly adjusted accel pump linkage and / or pump plunger travel. The bog at the last end of travel could also be a restriction in the main jet fuel passage. Float level is also important to keep the carb bowl full.
Not fuel related but a big factor is to make sure your ignition settings and timing are correct.
Hope this helps you
Mike
