Technical Front carb whistles!

This is a set of rochester triple two barrel, not original but modified to look original, the front carb whistles on throttle blade tip in. I don't see any different from it to the other two, I have adjusted the throttle blades so they are sealed when seated, none of that sealant goo was added, they set naturally tight to the venturii wall. It is not very loud but its there and a puzzle, any ideas?
sbc with early edelbrock intake, small base rochesters.
Thanks, Oj

 

No clue, but maybe a small burr or sharp edge on the throttle blade is the culprit. Try stoning the edge of the throttle blade. Is it also possible the throttle shaft bore may be worn? Another trick may be to swap the carb positions and see if the whistle stays with the position or moves with the carb. Good luck - let us know of the resolution.

 

Swapping front to rear is a great idea! Thanks for that Frenchie.

 

Does this occur with and/or without air filter(s) installed?

 

Had one that had a whistling gasket. Drove me nuts trying to find it.

Air was getting ****ed in past the base of the carb. The carb base was just a little warped a teensy bit and needed to be tightened a bit more.

 

No air filter, going thru initial startup/troubleshoot

 

You could always put a harmonica on the other end carb. ?

 

I understand the annoying part when everything looks tight and good. If I was in your spot I'd grab a 2-foot-long piece of rubber Vacc hose and go hunting. I'd set the throttle so it's making the noise, stick one end of the hose in my good ear (I only have one) and start moving the open end around the Carb in question till I located the sound. It's just like using a Stethoscope and works. Then I'd address the issue and move on to next little problem.

 

X2, I ended up having to mill the spacer under the Autolite 2100 and installing a thicker gasket.

 

It only does it as the throttle blades sweep open, not continuous, it sounds like that whistle in cartoons when somebody falls on their ***. I had a 4bbl that did that when the front and rear linkage was connected 1:1, not progressive, it was louder and annoying so I put the stock Holley linkage bar back in.

 

Could it possibly be around a throttle shaft? Lippy

 

If you squirt some ether (starting fluid) around the throttle shaft on the outside of the carb, and the RPM changes, air is getting ****ed in there and whistling dixie.

 

I had it back apart yesterday dealing with intermittant dribble and found the seat part of the needle & seat bore to be overly large and allowing the needle to seat at a slight angle in the bore so it wouldn't shut off the fuel proper. We'll see if the whistle is still there now that all 3 carbs are starting to work right.

 

If that doesn't work check your hearing aid batteries. Worked for a friend of mine.

 

Keep the hood closed and tell everyone it a Rochester FI…. Guys set them to whistle.