BigT-65

I am rebuilding my Carter AFB 3720SB carb and noticed that it looks like the secondary lockout dog is not installed in the right position. My question is: How hard is it going to be to remove that screw so I can move the lockout dog where it should be? I put a large screw driver on it and put some serious pressure on it but it did not break loose. I don't want to screw it up, but I have pictures showing this screw removed. It's not very long, maybe a half inch.
???

KC John

If you can hold the carb from moving, you might get lucky tapping the screwdriver with a hammer while trying to loosen the screw. I assume you used some type of penetrating oil.

BigT-65

I did put some liquid wrench. I tapped on it for a while with a pair of pliers. It doesn't have reverse threads does it?

W Guy

Nope. Standard threads. You can try heating it. That might help.

Verne

Frankie the Fink

Just so we are all on the same page -- you DO know that the secondary lock out should only "lock out" when the choke is on ? Correct ?

I can't tell much from the pics but I wouldn't want you breaking something trying to fix a non-existent problem !

W Guy

In the photo you can see that it is installed upside down.

Verne

Frankie the Fink

You're right I didn't study the second pic as closely - very apparent.
Its real easy to strip screw heads and threads on these old carbs.
Just for grins I think I would try the old mechanic's trick of melting some candle wax in and around the screw head and let the carb sit for a coupe of hours before trying to loosen the screw.

The wax will 'wick' down into the threads some times and loosen things up - doesn't always work but less 'medieval' than heating things with a torch.

BigT-65

I do know that it's functional when the choke is on, but because it's upside down I think it's getting in the way of other moving parts. Now if I was gonna heat it up I should heat up the area around the screw, right. screw needs to be colder. I am not going to use heat until the last resort. I might also try the wax.

PAmotorman

heat from a berz a matic torch on the aluminum should loosen it up.

BigT-65

I am about to give up trying to get this screw out with Liquid Wrench and a screw driver. I think at some time in the past someone glued the screw in with super Loctite or something. I was wondering though, if the carburetor cleaner I soaked it in overnite would have loosened that up. It just doesn't seem like it would be rust. The carb ain't in that bad a shape.

W Guy

Check your personal messages. It shouldn't be that hard.

Verne

BigT-65

I took the suggestion from W Guy. I thought I had a socket with a screw driver blade but I could not find it. So I figured I would just put a pair of vice grips on the screw driver shaft to get the leverage. And it came loose. After re-positioning the lockout dog I realized that I have other linkage problems. I was starting to think someone in the past changed some of the linkage parts and they are not original. But I just found a picture of a Carter AFB online that looks like it has the same parts as mine. I'm gonna see if they match up.

BigT-65

I have a Carter AFB 3720SB carb. I need some good photos of the linkage setup on both sides of one that is known to be correct and good. Mine is not opening the secondaries on full throttle. There are various lugs contacting other parts that are keeping it from opening up all the way. If someone had one of these that they could take some pictures of you could make me real happy.

W Guy

These are pics of a '63 300hp carb. All the linkages are the same configuration as yours.

Before:


After



Hope this helps.
Verne

BigT-65

I think it will help a lot, Thanks. If this is one of your restorations, you do good work.

W Guy

Yes, that's my work. Thanks for the compliment.
Verne

BigT-65

With the help of all who replied, I got the Carter setup properly and back in the car. Everything seems to be working as it should now. Thanks