I have a 750 Holley with vaccum secondary's and they don't work. I punch her down and they won't open, anyone know what is wrong? (I even ran a 13:3 in the 1/4. with 2 barrels!) I thought about a lighter spring. What do you think? Thank's for your time; Mike
Are you Sure they arn't opening... I couln't tell when the Secs. on my 750 opened either (the transition was too smooth). You can try lighter springs, My 455 loved the lightest spring there was. Go out and buy the "Trick Kit" for it, alon with the adjustable spring Secondary diaphram setup... only cost about 40 total for both. You usually ruin the Diaphram when changing the spring (at least mine did) The adjustable housing makes it a snap to switch springs.
yeah I'm sure there not opening... I rode in one that did work. Thank's for the advise. I appreciate it. Mike
Well, check your diaphram for holes. Check your vacuum passages for clogs. Check the little round check ball in the vacuum port. Make sure the secondary shaft rotates freely. Then try the lightest spring. Just for your info, the secondaries will not open by just revving the motor in neutral. The motor has to be under load. And you can't always "feel it". In fact, if you feel the secondaries open, they are opening too soon or too fast. It should be a smooth transition. Have fun.
New one. I just bought a new Carb. Nothing really wrong with the 750 I guess. I went to the Holley Street Avenger 870 cfm. I needed more carb anyway with my setup. I should get a few miles on it before storage takes over. Thanks for the advise. I love learning this stuff! Mike
