Holley secondaries won't open

There is no reason to not take the vacuum assembly off and no reason to not dissassemble. If that other guy thinks the rod needs bending....then you need to stop listening to that guy!

It is easy to test: Take it off the carb and you will see a small air passage hole in addition to the mounting screw holes on the flange where it mounts to the carb. Place a small hose with a clean, straight cut end surface tightly over this hole so that it is well sealed (vaccum hose works well) and suck on it; the rod should move and you should not be able to suck any more air. Try to hold the vaccum by moving the tip of your tounge to seal the hose; the rod should not retract. (Or rig up a vaccum source to do this; the hard part is sealing the hose against the vacuum assembly.)

If this does not work then either:
- the small check ball inside is stuck and not allowing vaccum to pass through the air passage in the mounting flange to reach the diaphragm
- the diaphragm is busted if you can continually suck air

You can disasseble these easily; just be careful to not have the screws snag the diaphragm while turning them and tear it. Also, check the seal of the vacuum assembly against the carb body where it mounts up to the body.

A normal vaccum leak in the intake below the throttle plates has no effect on this unit becasue they do not work from that vaccum. These work by vacuum generated in the carb throat ABOVE the throttle paltes that is generated by airflow down the carb throat. The reason it is hard to impossiblwe to activate these secondaries whil sitting still is that you can generate this throat vaccum only very briefly by opening the throttle sitting still, but you cannot create the needed level of throat vaccum for long enough without the engine over-revving and blowing up. This vaccum has to exist for a certain amount of time to move the diaphragm and you can't do it long enough just revving the engine.

If the diphragm checks out good off the carb, but the paper clip test does not show it moving, then the air passage inside the carb from the mounting flange on the body down into the primary throats is probably blocked. Shoot some carb cleaner into the air passage hole where the vaccum assembly mounts to clean it out as se if that fixes it.

These are really not all that hard once you know how they work. Good luck and let us know how it turns out.