[Hotfingrs]

When the acc pump lever is pushed, the gas comes out the squirter. You could need a larger amount of gas for the transition, so you would need a larger squirter size.

The accelerator pump nozzels or “squirters” are sized according to the size of the carburetor. Different intake and cylinder head combinations may require more or less pump shot. If the engine seems to have an off-idle stumble, changing the size of the squirter itself can fix this issue. The first thing to do is determine whether it’s a lean or a rich stumble.

If the engine seems to take a deep breath and then accelerate quickly (almost like the iginition cuts off for a split second), it’s generally a lean stumble. Check the size of the squirter on the primary side and install the next largest size. If that seems to help, but not completely eliminate it, try increasing the size of the secondary squirter.
If the engine seems to have a “blubber” or is lazy to accelerate then cleans up as it builds RPM, it’s generally a rich stumble. Check the size of the squirter on the primary side and install the next smallest size. If that seems to help, but not completely eliminate it, try decreasing the size of the secondary squirter.