I noticed the center carb has a much weaker pump shot than the end carbs. I am assuming they should all be the same as they are all 30 cc pumps. If I measure the movement at the pump end of the lever, I get about 1/16" on the center carb and 3/16" on the end carbs. However, if I swap the lever and the plastic cam with one of the end carbs, the lever movement is still 1/16" for the center and 3/16" for the end carb. I don't see any reason for the disparity. I tried several cams and levers from other Holleys with no change. The distance from the throttle shaft to the edge of the plastic cam is the same on both as well.
Holley sells a kit with different cams. I'm sure there is one that would help but I would rather fix the underlying problem. Anyone encounter this problem?
Well, I think the small amount of fuel that comes out is due to the minimal movement in the lever. I get a good pump shot if I push down directly on the accel pump arm. Thanks for the reply, all good things to check
I would take a closer look att the pump cam mounting screw holes position on the throttleshafts to see if they are in the exactly same position on the center carb as outer carbs. Like position #1 gets a different ramp on the pump cam than position #2 will.