[1ownerT]

This is a very long shot, but possable. Several years back I bought a Holley 750 vac secondary, new out of the box it did not have the acceleration I thought it should. I had a secondary spring tunning kit and went to do the same as you (install the lightest then work heavier) when I removed the secondary chamber it had a solid gasket in place where it should have had approx a 1/8" opening in the center of the gasket. It could not get a vac signal to open the secondarys. I replaced with the proper gasket and proceeded to my "test track", where on my first pass I twisted the end off of the driveshaft.
They have done it once, maybe they did it a second time?

[Viet Nam Vette]

Originally Posted by 1ownerT

This is a very long shot, but possable. Several years back I bought a Holley 750 vac secondary, new out of the box it did not have the acceleration I thought it should. I had a secondary spring tunning kit and went to do the same as you (install the lightest then work heavier) when I removed the secondary chamber it had a solid gasket in place where it should have had approx a 1/8" opening in the center of the gasket. It could not get a vac signal to open the secondarys. I replaced with the proper gasket and proceeded to my "test track", where on my first pass I twisted the end off of the driveshaft.
They have done it once, maybe they did it a second time?

Heh Thanks for the Reply 1 OwnerT....

Good point. I also had bought the Kit with the removable Diapharam top. This lets you remove the top cover to change springs with out removing the choke and Vacuum diaphram assembly.

Of course to install this cover you have to remove the vacuum diaphram. In the kit is a brand new cork gasket. It is mounted on an adhisive backing ..and you peel if off and install it on the chamber.

Now ..I can see how this happen to you as you must remove the center piece of cork from the ring before mounting or sticking it on to the chamber.
So..when they built yours ..someone forgot to remover the center!!!

So....Good call ..but I did install it and I know I removed the center piece.

[1ownerT]

It was worth mentioning, you never know. I don't think the removable covers were available when I was tunning on mine. It was a PITA to have to remove and replace the thing to change springs.
Hopefully you find the culprit soon.

[coldknock]

I forgot to mention that with the short yellow spring the secondaries begin to open much sooner than 5200, on my engine anyway. That's the rpm in which they are completely open by. With 100 extra cubes and much better heads the airflow should be more than enough to open them up sooner with the same spring, even in an 850. Oh yeah, I tossed the check ball too. It made them open too slow for my taste.

Just try it.


Larry