i just bought a holley carb. off ebay for $17. it's complete with no rust or corrosion exc. in the bottom of the fuel bowls on the butterflys (i think that's what they're called). it's a 650 single pumper. holley #7448 and i'm told that it's a direct q-jet replacement. it is, of course, a squarebore. i removed the bottom plate where the "butterflys" are and i used PB Blaster, Kroil, and carb. cleaner on it to no avail. i also scraped, very carefully, the rust/corrosion around the butterflys with a small flathead screwdriver. still no movement. i forgot to mention, the smaller butterflys are the ones that are frozen (the secondaries, i guess). the larger ones i think would move freely, but are bridged to the secondaries. i think the problem is that the shaft that goes through the plate from side to side is corroded as well. is there something i can soak this thing in that'll free up these parts? worst case scenario, is it possible to get a replacement base for this carb? sorry for the rambling and, as always, any help is greatly appreciated.

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scott--one owner '72 RS

If it's a Qjet replacement and it's got significantly smaller throttle plates on one side than the other then it's a SPREADBORE carb.

The little throttles are the primaries (connected directly to the throttle arm where the throttle cable hooks up). The big ones are the secondaries.

Yes, it's possible that the throttle shaft is frozen inside it's bushings. It's also possible that the throttle shaft is mechanically jammed against something either on the throttle arm side or over in the choke linkage on the other side of the carb. It's also possible that the throttle shaft is bent and/or the entire baseplate is warped- although that would usually just make it "sticky," not totally frozen in place.

If it's really just rusted/corroded where the throttle shaft goes through the baseplate bushings then overnight soaks in penetrating oil followed by firm but gentle back-and-forth twisting of the throttle arm will usually start to work it loose, although it make take an almost PAINFUL amount of repetitions sometimes before it moves smoothly again.

i meant spreadbore. i don't know why i said squarebore. what's a good penetrating oil to use? can i remove the butterflies from the shaft, using the screws, and "press" the shaft from the baseplate? would that speed things up and decrease damage to the throttle arm? i could always just take it somewhere and have someone experienced do it, too.

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scott--one owner '72 RS

try putting it in a bucket of diesel fuel or transmission fluid and just let it soak for a couple days. You need to give it time to penetrate the shaft.
Then as Damon said, work the shaft back and forth however much you can, as soak it again.

It may take a several repetitions to get everything conpletely freed up, but the last thing you want is to bolt it on, only to have your throttle hang WFO because there was still a small amount of corrosion left.

Scott, yes, you can remove the butterflies from the shaft and try to TAP the shaft out with a drift, working and wiggling it as best you can during this process. It's something that you'll just have to get a "feel" for. Again- firm but not swinging for the fences.

When you remove the butterfly screws remember to first file off their swedged (mashed) threads sticking out the backside of the throttle shaft. If you try to unscrew that mess without grinding/cutting them off first you'll butcher the throttle shaft threads for sure and maybe even break the threads off completely in the shaft rendering it useless.

i put the baseplate in diesel fuel yesterday. i'll let it soak for at least 2 days. i'll keep everyone posted.

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scott--one owner '72 RS