It's always something

[Texasdoc]

Originally Posted by FWB

i don't get what you mean by the accel pump won't make fuel come out of the boosters
<snip> so arm pressing on diaphragm......squirts fuel......

Activation of the accelerator pump causes fuel to come out of the squirter, not the boosters.

Originally Posted by FWB

right from holleys instructions, i'm sure all of you know much better than holley

The accelerator pump should be adjusted so that the slightest movement of the throttle lever results in actuation of the accelerator pump. The pump override spring adjustment is checked while holding the throttle in the open position and the pump operating
lever held in a fully compressed position. The clearance
between the adjusting nut and the arm of the pump lever should be .015”.

Yep!

Originally Posted by FWB

and a note for "experts"

Originally Posted by FWB

NOTE:
Under no circumstances should the pump override spring be adjusted to permit coil bind (or bottoming). This is
sometimes recommended by some “experts” as a means to a quicker delivery rate and increased flow. A
ll that such “adjustments” accomplish is to provide bent accelerator pump actuating levers and ruptured pump diaphragms.
Override springs are carefully sized to provide proper delivery pressure without damaging vital carburetor parts by
momentarily absorbing pump force and regulating the pressure peaks within the system

Yep again. You want immediate movement of the accelerator arm with any throttle movement. You DON'T want coil bind (bottoming or stacking the coil spring) at WOT. THIS will over pressure the diaphragm, causing a tear.

The spring stays in a relaxed state from idle to near WOT.
As the throttle/accelerator pump arm nears WOT you want to run out of throttle motion first, before you reach the end of travel for the pump arm. There should be 0.015 inch travel of the pump arm remaining once you hit WOT with the throttle. If you hit the max travel of the pump arm first, further travel of the throttle will start to compress the spring. Once the spring compresses completely, this is called stacking or coil bind - it cannot compress anymore. After this point, the weakest spot in the system is the pump diaphragm and it will tear as it gets over extended.