A couple of things about vacuum secondary carburetors. First, if you can feel the secondaries open, they are not adjusted right. The car will be fastest when the transition into the secondaries is invisible. Secondly, as stated above, make SURE the little cork gasket is between the secondary diaphragm housing and the main body. If you leave it out, the secondaries either will not open, be very lazy, or not open fully. Also, I do not recommend removing the vacuum secondary check ball. This causes the secondaries to open to "hard" and will actually slow the car down. I did not see where you said you actually tested the secondary diaphragm. Remove the housing. Then depress the diaphragm rod into the housing and put your thumb over the vacuum port and then release the rod. The rod should not return all the way back out. It may come out some from the spring pressure, but if it comes all the way back out, the diaphragm is bad and should be replaced. If it's good......or when you repair it, do the paper clip test. Don't blab about not doin it on the forum. DO IT. That's the only way to verify operation or the lack thereof. Bitchin about it on the forum won't confirm anything. No offense. When you get a vacuum secondary carburetor right, you'll KNOW it. There will be no question. I know a lot of guys on here like the double pumpers and they have their place. But IMO, on a mild to even hot street/race car with an automatic, the vacuum secondary carburetor is really had to beat.
ale:
