I've been working on cleaning up the carbs that I have. Some of the throttle shafts are frozen in place, so I started looking for solutions. I stumbled on a product called Evapo-Rust on the internet, later figured out that they carried it at AutoZone. For $10 you get 32oz of the stuff. I was skeptical, didn't think it was going to do jack, so I didn't take any photos of the rustiest parts that I put in it. But I have got to tell you, this stuff actually works pretty well, especially on small delicate parts you don't want to be sandblasting or sanding. Some of the throttle plates I had were caked in rust, and after an overnight soak, had no rust left on them at all.
I took one of the throttle shafts, and placed it in the Evapo-Rust last night.
The after photos were taken before the parts were rinsed off, which makes them look even better. In the last photo you can see where the arm wasn't submersed and is still caked in rust, compared to the part that was in the solution. The first few parts that I soaked had far more rust then this piece, and came out looking just as well.
I'm really surprised how well this product actually works. I expected it to do nothing, and it's actually turned out better then I could hope. The best part is that Evapo-Rust isn't acidic, or nasty at all. I only have 32oz of the stuff, so the only way I can submerge the carburetors is by putting it in a trash bag, that way I can draw it up around the carburetor. It's been in that bag for 2 days, and there's no sign that it has done any damage to the plastic.
This product may have limited abilities, since you need to soak the parts to get the most out of it. Even so, I've found it incredibly useful in smaller parts, like these carburetors. I've gone ahead and ordered a gallon of it, which is only $27, including shipping. It's definitely a product I will like having around, and I would recommend it to anyone doing work like this.