I have been chasing my tail on this hesitation, it occurs between about 1000-2000 rpm. When I accelerate from a stop it feels like the motor is not getting any gas but as I back off the throttle it picks up. Once it is over that rpm range the engine accelerates fine. I have tried more advance and less advance on the ignition with no luck it gets worse either way although it seems better with less. I opened up the carb and cleaned the jet and the needle next to it, checked the float and gaskets. It idles smooth and revs in neutral OK but if you rev it quickly it stumbles a bit. The accelerator pump works but it seems like it is a fuel delivery problem, is there any tuning or adjustment to the accelerator pump? I didn’t see any
