Carburetor Question - Is this a good call?

Mattax said
IF there's no fuel at first movement (65Val's test), this is the pump lever he was talking about.
View attachment 1715460014

If its the pump cam that Holley installed, all that should be neccessary is adjusting the spring loaded bolt so there is zero play at idle.
If the pump cam has been changed, sometimes its neccessary to reshape the arm (bend) so it contacts the cam where it will do good (upper arrow). Also make sure the lever is not contacting the throttle spring next to it.

If fuel is still not appearing immediately, then check valve (umbrella valve) could be damaged.

I think I know why MO mentioned power valve. If you get a part throttle flat spot at higher rpms, that would be a possibility for sure.

Perfect pics thanks Mattax - I actually tried to adjust that screw so there would be zero play against right where that red arrow is pointing to the arm.. I cant loosen it enough to make it have zero play.. I set up my phone and took a video of the carb when i was having the first aforementioned issue with vacuum and caught the adjustment we're discussing and caught that movement.. (ok cant upload a video clip so i'll take two screen shots.. one at rest, one with throttle - see below)

Whats not obvious is that the arm for the accelerator pump DOES move.. just not a lot.. and no amount of loosening will make it really change anything visually on that movement.. seems to always make TOO much contact