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Holley vaporizer air damper

Posted: Sat Apr 03, 2021 9:34 am
by sla974
Hi, I'm trying to get my great grandpa's 1926 Tudor running up to snuff and the Holley vaporizer has a lot of vacuum leaks so I ordered a rebuilt one from Blue Oval classics. I got it yesterday and while changing it out I noticed that on the rebuilt one, the air damper/dampner? was spring loaded somehow to about 25% open. From many of the forums I have read on in the past, I thought I understood that the air damper/dampner thing was weighted but free swinging. Which way is it supposed to be? Any advice would be helpful!

Re: Holley vaporizer air damper

Posted: Sat Apr 03, 2021 10:30 am
by JohnM
What you call damper, I assume you mean the throttle or choke butterfly. The throttle is closest to the intake manifold and is not spring loaded. The choke valve you can see at the intake opening should be spring loaded to hold it open to about 90 degrees. I just looked at what it costs for a rebuilt vaporizer. At that price your choke valve should be properly set.

Re: Holley vaporizer air damper

Posted: Sat Apr 03, 2021 10:34 am
by Scott_Conger
Take a look at this cross section drawing and you'll get an idea of what it is, and why it probably looks that way: app.php/gallery/image/637

Re: Holley vaporizer air damper

Posted: Sat Apr 03, 2021 12:27 pm
by katy
If you mean the "air flap" (as per Scott's drawing) it should be free floating.

Re: Holley vaporizer air damper

Posted: Sun Apr 04, 2021 12:33 am
by sla974
Yes, it would be the air flap. Its between the choke butterfly and the throttle butterfly. In the original I have it is free floating, but in the rebuilt one I just received it is spring loaded at about 25-30 percent open. Should i go ahead and try it or call them and see if they have an explanation why they rebuilt it this way?