Idle tubes (removal or leave alone)

[GSP7]

In Cliffs book it shows removing the idle tubes. Looks like a good way to destroy or damage them.

Ive never removed them before when rebuilding years ago. I just blow carb cleaner through them to make sure they are clean... My carbs are not corroded

Comments

[Kenth]

The idle circuit in yours 1980 350 HD Truck Quadrajets is plenty generous with .038"-.039" idle tubes, .053"-.057" idle down channels .069 upper idle air bleeds,.062" lower air bleeds and about .105" idle bypass air.

If the tubes are clean there is no need to pull them out.

These 1980 Truck units don´t need much, if anything, for high performance usage.
If anything, cut the stop on air valves for full flow and use DA or CE secondary rods.

[GSP7]

Thanks

The '81 k20 4x4 truck is well takin care of, is just a driver, with mildly built engine is well babied, , Has a 73 date cast #010, 4 bolt block with 1970 cast #*****441 heads 1.94 in 1.5 ex, Elgin RV cam, headers

[Cliff Ruggles]

It is IMPOSSIBLE to effectively clean idle tubes by blowing carb cleaner or anything else thru them.

The MUST be cleaned manually by "rodding" them out of with precision drill bits. 

It's one of the biggest reasons why many "home" Quadrajet rebuilds fail or don't make the grade once the carburetor is placed back in service, even if you do EVERYTHING else right.

Decades of use, drying up cycles, etc will leave layers of "varnish" in the tubes making them smaller and often completely plugged up.  It's rare to see an idle tube that isn't restricted some when I pull them out for cleaning.

Don't worry about damaging them, I sell new ones and have plenty in stock......