The Stovebolt Site Forums The Shop Area Engine Shop Vacuum Advance/starting problem

On my trip home cross town my 216 started hesitating horribly on the bottom end but would clean up with a good amount of throttle. I checked and found the vacuum advance not moving at all. I used a vacuum pump...nothing moved, moved the manifold hose to the advance unit and ...more nothing.
So new advance unit has been ordered.

The engine would (until this happened) start on the first try with one pump of the accelerator and just a bit of choke. Now I am having to pull the choke almost all the way out and work the throttle a bit. I did have 2 backfires through the carburetor while trouble shooting this issue. Does vacuum advance have any effect on start up? Or is there more likely another issue at play possibly caused by the backfires?
I have the vacuum line at the carburetor disconnected and the port is plugged.

Jackie

The vacuum advance should not affect a cold start at all. Those backfires could have damaged or collapsed a float if you've got the usual float made of thin brass. It wouldn't hurt to open the carb up and check the float level, etc.
Jerry

I checked the float and found it to be in good shape did the hot water test for leaks and none found. I had to adjust the drop from 2.25 to 1.75 the level was ok.
I replaced the vacuum advance unit,cleaned plugs, adjusted points,adjusted timing and fuel mixture using a vacuum gauge.
The accelerator pump does nothing when moving the rod slowly if moved quickly it squirts near the end of the stroke. It seems very erratic to me. I disassembled the carb (Rochester "B") again. The leather on the accelerator pump has cracks. Looking in the bore for the pump I can see a ball in an orifice at the bottom that will not come out is this the intake port? Or does the fuel over flow into the bore from the bowl? Any method for removing the check ball if need be?
During the bench test the pump would work as far as discharge but would not refill unless I filled the pump.
Accelerator Pump well