line from exhaust manifold to carb?


Sharpest Tool
Nov 13, 2010
Willys Model
Willys Year:
While I was pulling my carb off to be rebuilt, I noticed there was a steel line from the carb to the exhaust manifold. The line was broke right at the manifold. It looks like there is no way to repair the spot that it attached to the manifold. What is the purpose of this line. What is the effect of it being open to the air. Any way to rig this back to the manifold? Or should I just cap it off?
It most likely is a heat tube for the choke assembly, but that would not make sense if it has a manual choke. Right off hand I can't think of any thing else.
Sounds like the choke heat tube as previously stated. If it is, and it is broken off, the choke may not open up fully when the engine is hot. I have fixed them by drilling out the broken off piece out of the exaust. just use a drill bit the exact size of the tubes outer dia. Copper tubing works good as a replacement tube since it won't rust.
Do you have a photo?
Jeff has got you fixed up there, Paul. That's exactly what it is and that's exactly how to repair it. If you don't have an auto choke on your carb, then don't worry about it, but it sounds like you do.

If that line is hooked up to something on the carb other than the choke's wrong.
I talked to guy who is rebuilding the carb. he said it is for the choke, but I also have a manual choke, so I will probably just cap off the hole on the carb.
I guess my carb did not have a spring on the choke before, so it would stay open unless closed manually. The guy that rebuilt it put the spring back in, so now it wants to stay choked. Either I need to fix the line or removed the spring.
Does anyone have a picture they could post showing the exhaust manifold to choke connection? I'm rebuilding a 55 Pickup with the L-226 and a Carter WCD 2204S carb and would find it helpful.
Here's a couple pics of mine, I have the exact same engine and carburetor on my '56 pickup. The line is metal, covered with some fabric insulation. The first pic shows the front of the carb, facing the firewall. The second pic shows the connection to the exhaust manifold. Hope this helps!

I think this carb originally had an automatic choke, which my dad converted to a manual choke. So I'm guessing that the exhaust line on mine doesn't actually do anything useful anymore?

Yep, that helps immensely. I love seeing these old engines in all of their funky configurations. I was assuming the heat tube went into that spot on my exhaust manifold, but I have absolutely no evidence that there was ever a tube there. This clears it up for me. Thanks!