Manifold Vacuum Experiment

Aight den. I need some ideas. This carburetor has what I call "pink" pump cams on it. I have adjusted the pump correctly, tried both holes in the cam. Hole #1 works better, but I still have a stumble right off idle and I KNOW it's the primary accelerator pump, because I can see that it's a weak shot. The secondary side is like Niagara Falls, but the primary side is weak in comparison. I've disassembled it and run small drill bits into the carburetor body through the pump passage and down the nozzle hole on top to make sure there are no obstructions. Blew it out real good with the air hose, but the pump shot is still weak. Any ideas?

The blue cams have the most lift and duration. I think the pink cams are right in the middle.

One thing I’ve been finding lately is the part of the lever that rides on the pump cam has to be “tuned up” so that it lays flat all the way across the pump cam.

If that lever is riding on just the edge of the pump cam, it changes the geometry and that affects the pump shot.