View Full Version : Holley carb

08-01-2013, 06:55 PM
My holley carb is not opening the back two butterflys. I have put a new diapharm in the vent to open the back two but still nothing. When i reach behind me and open them by hand it really picks up. I will get some pics this weekend

08-01-2013, 06:59 PM
There is a vacuum passage the allows the secondaries to open when a minimum level of vacuum is reached. It is possible that the passage is clogged due to age, or you are not hitting a low enough level of vacuum to allow them to open. You might hook up a vacuum gauge to determine what is going on.

This will all have to happen on the water. You can't, and don't want to, get the secondaries to open up while running in the driveway. Reaching back to open the secondaries is kind of fun.:rolleyes:

08-01-2013, 07:40 PM
It is fun when the back opens up yes I will have to take another look but it dose run nce on only the front barrels and is probably better on gas

08-01-2013, 08:08 PM
Definitely easier on gas when the secondaries don't open. They flow a lot of fuel.