Carburetor Vacuum Leak

[cwestra]

I appear to have vacuum leaks coming from around the shafts on all 3 of the carbs on my 340.  I can spray concentrated carb cleaner directly on the shaft end and the engine speed increases dramatically.  And I am pretty sure it is coming from this area because I stuffed a shop towel underneath to cover the base gasket.  Pulling apart one of the carbs I can see about .015" - .020" of up and down play between the shaft and bore.  What is normal here.  Did they ever put bushings in there?  If this is worn too bad, do they make bushing kits for them?  It this a common place for vacuum leaks?  Any help would be greatly appreciated.

[Moparal]

yup, you need a holley bushing kit. Before you can even begin to tune your carbs

[cwestra]

yup, you need a holley bushing kit. Before you can even begin to tune your carbs

Any recommendations on where the best place to get them is?

[cwestra]

I just measured the bore and shaft on one of my outboards.  Bore on both ends measure out at exactly .375".  The shaft, measured in the area contacting the bore comes out at .364" and .363".  This means I have .011" to .013" of side to side play between shaft and bore.  With the aluminum being the softer material, I am sure that it wears more than the shaft.  But in order for it to have worn, it would have started with a bore closer to .365" in order to get a good fit with the shaft.  That would just seem odd, however, for a 3/8" nominal shaft.  And measuring the shaft at a location farther out where it is not bearing against the bore I do get the same dia. measurement (.364") so I am confident that the shaft has not worn.    In other words, after measuring the bore diameter at exactly .375", I would have thought for sure this would have been good, since it is exactly 3/8". 

Also, there is a machined step in between the bearing surfaces on the shaft measuring .352" dia. and .342" dia.  Can this area be used to secure a teflon shim (.010" thick and .015" thick, respectively) instead of boring and resizing for a bronze bushing?  It seems the bushing repair kits I've seen come with an expensive boring tool that can be used multiple times.  I only need it for one time. 

Any insight into this problem would, as always, be greatly appreciated.

[vinb]

If you need to do your throttle shafts , look at this site..

http://www.supercooltools.com/html/ZA-ATS/index.html

[cwestra]

If you need to do your throttle shafts , look at this site..

http://www.supercooltools.com/html/ZA-ATS/index.html

Thanks, I did see this.  It's exactly what I need, however, I am trying to get buy without spending $170 on it, though.  What would be great is if I could find someone who had the tool that I could rent for a few days.  Then all I would need to do is get hold of the bushings.  The tool is the expensive part.

[vinb]

Yep, I may buy that kit later this year. I have about 6 or 7 T-Q's I want to do..