Corroded Carb Fix

[60s Refugee]

I was wondering if there is a preferred method to free up corroded moving parts in an old carb?

I have a couple of Autolite 1100's ready to begin rebuilding. One is real good, the other all seized up. The last time I tried to do this the idle mix screw broke off and I had to send out for a Pony rebuild. There wasn't a replacement screw in the rebuild kit either, so drilling it out might not have resolved anything. My first thought is to throw it into the carb soak bucket and leave it there for a few days. Trouble with that is that it might ruin the plastic parts. Before I break off another idle mix screw I thought I'd search the knowledge base here!

So, what would you do?

Harry

 

[fordconvert]

You can try a bit of heat. Propane is usually fairly safe on aluminum. Work the screw back and fourth, dont just try and crank it out.

 

[addo]

I think vinegar gets a good rap in some quarters, too. From my understanding, it eats the rotten bits far quicker than it damages the virginal metal.

 

[60s Refugee]

OK. I fixed it!

Today I got the idle mix screw out. Here's how:

First, I took the carb apart. I thought I'd try soaking it first and to do that I had to get the plastic venturi out. The venturi is held in by three crimps and the SCV port nozzle. I took a Dremel tool with a cutting wheel and carefully ground off the crimps. The nozzle was another matter. It's pressed in with nothing to grab onto to remove it. Since I will not use the SCV on this carb, I just took a 1/16" drill and drilled it out. With that done, the venturi came out easily. I placed the parts in the carb bath and let it sit for two days.

So, yesterday I tried to get the screw out. No luck! Wouldn't budge!

So I put the lower half into a vinegar bath. Left it over night.

Tried it this morning. Still stuck. Wouldn't budge!

So I got out the propane tourch! I placed the carb in the vise (carefully) and heated the carb area where the screw is. Heated the screw too. I was nervous about not getting it too hot! The spring around the screw began to glow red hot. I tried the screw driver...it moved! About 1/16" each way! I heated it more. It moved more! About 1/4 turn. I oiled it, screwed it in and out, still wouldn't come any farther out. Heated it more. Tried again. Half a turn out now! Oiled it again. Screwed it in, then out. Finally, it broke free and screwed out. The threads are still good, screw OK.

So, fordconvert, you were right, heat does work!

Thanks for another lesson well learned.

Harry

 

[mugsy]

Propane = mini-smoke wrench (spanner for you non-US guys)!!