Removing Idle Tubes

[brown7373]

I am having no luck removing idle tubes.  I have followed the procedure in your book, Cliff, and am getting nowhere.  The tubes are off the collar, but the collars won't budge.  Drywall screws have failed, and heating the area with a torch has also not let me get them out.  Any other ideas?  I have considered a drill bit, but I don't know.

[429bbf]

im not the carb god. but I've taken out a number of idle tubes. does your screw seam to be slipping when you go to pull it out?grind the first couple of threads off the screw so it can get a better bite. if that doesn't work get the right sized punch that just a few thousandths smaller than the collar and drive the collar down just a smidge. to loosen it in the bore . then twist your screw in with a little heat on the carb and they should come right out.fwiw

[von]

In addition to the above mentioned tips I always heat the area just below the top of the idle tubes for 30 seconds with a small  butane torch, then put some pieces of masonite under my sidecuts for a fulcrum when prying up on the drywall screw. I've not had much luck getting them out without the heat. When driving the tubes down with a punch if the collar moves down too, drill the unit with a 3/32" drill bit about 1/4" deep to get a bite with the drywall screw. I always install new tubes since the old ones always get destroyed getting them out.

[Bigal442]

Great tip on moving the idle tube collars down a touch before extracting upward. I too have been struggling a bit with removal. Finally got one side out. The second side took a weird turn. The collar came out but the idle tube itself stayed in. I thought it would dump out just by turning the carb upside down. Not only did it not fall out, but I cant get it out. Why would the tube stick? I thought the tube just hung by the collar. I'm thinking I may have to use a tiny screw (I.e. Eye glass size) to go inside the idle tube to pry it up. Any ideas of what is going on?

Next problem is that one of the "idle down tubes" (next to the idle tubes) is missing! One side clearly has a down tube brass restriction while the other side does not. Are these available and are they just pressed in the the idle tubes? I have a picture but don't know how to post it.

Thank you.

[429bbf]

you may have tapped the tube down to far and now it is wedged ill bet when you get it out it my be bent.you can only go down very little that is why you don't have much room to gray the collar. your little screw should work. yes cliff sells the little inserts i think he also has screw in inserts you have to tap your carb. hth

[Bigal442]

I have attempted to attach two pictures with this post. One picture shows the empty hole where the downtube is missing with the removed idle tube. The other picture shows my stuck idle tube with the adjacent normal downtube.

Are the downtubes pressed in like the idle tubes? Let me know if I am getting the terminology incorrect. I did order the HP kit and more from Cliff last week and hope to get it today. I am building this carb for a 70 BB vette. May have to call Cliff for downtube help.

Perhaps a dumb question... what do the downtube restrictions do? As I understand it, fuel comes up from the idle tubes which is then passed over to flow down through the downtubes. Since the idle tubes are drilled to a precise ID to control flow does the diameter of the downtube even matter?

Thanks for any insights.

Allen

[429bbf]

what you are calling the down tubes would be idle channel restrictors . they are very important. they are so thin that you may have a piece of it still in the hole.you are correct the fuel as it is passed over as you say is also mixed with air from the idle air bleeds and then down the channel restrictors.these three things are very important to get right . they all work together.the little brass pieces are very thin and i feel some where out over time from dirty air filters . thats just my opinion.also from looking at your picture you drive the idle tube down to far and now its wedged. it won't be that hard to get out.fwiw

[Bigal442]

Thanks for further clarification. One way or the other I should be able to extract the idle tube.

Can you recommend what I should do to fix my channel restrictor problem? Is there a new part to buy and how to fix it?

[77cruiser]

Cliff has em, they have them here too.
http://quadrajetparts.com/rochester-quadrajet-parts-quadrajet-tubes-vents-c-128_36.html

Or buy some 8-32 brass set screws tap to fit and drill the size you need.

[Bigal442]

Got some new channel restrictors from Cliff. They come out easily if you drill with a .106" bit (Cliff tip). The new ones install easily with a light tap. I drilled them to .055" after installing them. Got the carb back together and on the car today. Seems to run well in the garage. Needs some choke adjustment to up the cold idle. Also need the rain to go away so I can road test and tune. Fingers crossed