Re: Now what do I do?! (Holley 1920 rebuild)
Post by tomkirkman on May 26, 2006, 1:05pm

That's the cam for the accelerator pump diaphram. Without it the engine will bog upon acceleration until engine catches up and pulls more fuel into the intake. The purpose of it is to squirt a little raw gas into the intake so you don't have an overly lean condition when you open the throttle.

The performance difference between an M715 with a good one and a broken one is night and day.