I have a 427/435 with a tri power on a 69 vette . Here is the problem at idle the rear slave carb is sucking air. I can set my hand over the front carb no prob as soon as my hand gets about 1" of the rear carmy hand gets sucked down and the car stalls when I pull my hand away it covered in gas. However I cant see a spray while at idle & the rear butterflys are not opening at idle so why am I sucking that much air?

I picked up a new base gasket and am going to put a machinist level on the manifold to make sure its not warpped.

Does anyone have a better idea???????

PS any pics of tri powers from the passenger side would sweet.

IF the throttle blades are seating properly it should not be sucking much air if any unless maybe some drilled holes in the throttle plates in a fine tuning attempt prior to you getting the car or carbs & intake.

Check the inkage to ensure it returning far enough for the rear carbs throttle blades to seat properlt with some pressure from the throttole inkage in general. I had issues like that with a 66 tri-power gto in the recent past and i had to re-adj the linkage for more push/pressure pushing on back carb to seatthe throttle blades correctly & stop it from sucking air. I also had to install a stronger return spring to hold more pressure on the overall throttle linkage to get all the throttle blades seated where they belong,after that things were good.

Isn't the center carb the one it idles on with idle circut on the bbc factory Holley tri-power setups?

But i would have to say if there are no holes in that rear carbs throttle blades that either they are not seating properly for some reason and someone mixed up the center and or end carb bases and the rear carb base is actually thre center carb base.

But it's been yrs since i messed with a bbc/holley tri-power setup so i am sure someone else with more recent exp with that setup will chime in to add more info to help you out like THE GUY HERE IN T/CHEVELLE (GENE?) WITH THE RED 66 CHEVELLE RUNNING A HEALHTY SOLID CAM'D 427 TRI-POWER & STICK.

Good luck.

Scott

I should have said I disconnected the mechanical return linkage and applied thumb pressure to assure the butterfly would be closed and same thing happened. I did have the carbs rebuilt a while back I guess its possible they mixed up the flys. I assumed they were all the same. I ordered a base gasket it was cheap enough so when I pull the carb I will check the blades.

Carlos,arent You The Guy I Helped With The Oil Questions ?

Scott

I had an erratic idle on my Holley-carbed Tri Power; the screws holding the throttle plates to the throttle shaft had loosened and the throttle plates were moving around preventing them from fully closing at idle--sometimes.

The Holley Tri-power carbs have an idle circuit on the end carbs. Helps keep the fuel in the float bowl fresh. Even so, the rear carb should not be pulling a noticeable amount of air at idle.

Chrysler Six-Pack (Holley carbs) had issues with base gaskets interfering with the throttle plates. Assure that the base gasket is installed correctly!