I've rebuilt my Carter YF carb for my '51 L110 with the 220 CI motor.

The engine seems to idle well enough (I don't have a tachometer so I don't know what the idle speed is).

The engine stalls/nearly stalls when I hit the throttle quickly. The accelerator pump seems to be working properly (I can see a stream of fuel spray from the accelerator nozzle).

What else could cause this problem? Is there an idle speed adjustment on this carb/engine setup?