Choke tube/air inlet hose installation

tmiken

New Member
Jan 21, 2008
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California
I've replaced a Holly Carb (electric choke) I had on my '65 fastback with the original Autolite 4100 (hot air choke) and wondered if anyone knew the placement of the choke tube and air inlet tubes?

Mine were broken off. I know the top tube goes from the choke stove to the carb, but am not sure of where the bottom tube of the choke stove is routed to.

I will be buying a choke stove rebuild kit to replace the bottom plug along with the choke tube kit in question.

When looking at the kits I see they come with an s-clip, insulation and also a rubber tube aside from the steel tubes but have no idea how all of it is supposed to go together. Maybe the kit has instructions. I guess I'll find out.

I have the shop manual but haven't seen a complete description; just diagrams relating to the top tube.

Any help would be appreciated.

Thanks!
 
The heat tube is attatched to the exhaust manifiold from the factory. If you have headers instead of cast iron, you will have to fab something else up.....

Thanks for the reply.

I have the original cast iron exhaust manifold on my fastback. I can see the top tube was snapped off and have read that I can drill it out. For the bottom plug, I have also found a nice article on how to remove it, replace the mesh filter, but what I am lacking, is after I purchase a choke tube kit; where the tubes actually route to.

The top tube should go to the carb as I can see a nice diagram in the shop manual.

I now need to find out where the "clean air" tube on the bottom came from.

Thanks!
 
Choke Tubes

On the 4100 you should have a cast tube just under the air horn of the carb pointing down at an angle. The rubber tube attaches here and to one of your new metal tubes. The tube with the 90 degree bend at the bottom goes from here to the bottom of your manifold. If you screw out the plug at the bottom of the manifold to replace the mesh, make sure the hole in the side of the plug points to the front of the engine when installed.

The other tube in your kit goes from the top hole of your manifold to the choke housing and connects with the ferrule and nut to the treaded part of the choke housing. This tube gets the insulation sleeve before putting it on the car.

The s-clip goes about midway down both tubes and just clips on the outside of the insulation on one and the bare tube of the other to keep them vertical and from rattling.

If you drill out the holes in the manifold you may have to push a punch into the metal tubes to swell them out to make them fit tight. If you do not have a tight fit they will come out due to vibration from driving.

Cold air travels from the carb to the bottom of the manifold and hot air up to the carb fromon top of the manifold. The mesh is actually not required. I do not use it due to over time it breaks down and gets sucked into the choke assembly. I run without the mesh and the choke works fine.

Your shop manual should have a picture of this under the Fuel Section. I have a 66 and it is very well detailed in the shop manual.

Good luck.

Good luck.
 
On the 4100 you should have a cast tube just under the air horn of the carb pointing down at an angle. The rubber tube attaches here and to one of your new metal tubes. The tube with the 90 degree bend at the bottom goes from here to the bottom of your manifold. If you screw out the plug at the bottom of the manifold to replace the mesh, make sure the hole in the side of the plug points to the front of the engine when installed.

The other tube in your kit goes from the top hole of your manifold to the choke housing and connects with the ferrule and nut to the treaded part of the choke housing. This tube gets the insulation sleeve before putting it on the car.

The s-clip goes about midway down both tubes and just clips on the outside of the insulation on one and the bare tube of the other to keep them vertical and from rattling.

If you drill out the holes in the manifold you may have to push a punch into the metal tubes to swell them out to make them fit tight. If you do not have a tight fit they will come out due to vibration from driving.

Cold air travels from the carb to the bottom of the manifold and hot air up to the carb fromon top of the manifold. The mesh is actually not required. I do not use it due to over time it breaks down and gets sucked into the choke assembly. I run without the mesh and the choke works fine.

Your shop manual should have a picture of this under the Fuel Section. I have a 66 and it is very well detailed in the shop manual.

Good luck.

Good luck.

Thanks for this detailed description. Due to the holidays I didn't get too far into this, but did clean out the choke stove on the exhaust manifold and am just waiting for my choke stove rebuild kit to arrive in the mail.

Your description was great and I do also have a shop manual for reference.

THanks again!
 
On the 4100 you should have a cast tube just under the air horn of the carb pointing down at an angle. The rubber tube attaches here and to one of your new metal tubes. The tube with the 90 degree bend at the bottom goes from here to the bottom of your manifold. If you screw out the plug at the bottom of the manifold to replace the mesh, make sure the hole in the side of the plug points to the front of the engine when installed.

The other tube in your kit goes from the top hole of your manifold to the choke housing and connects with the ferrule and nut to the treaded part of the choke housing. This tube gets the insulation sleeve before putting it on the car.

The s-clip goes about midway down both tubes and just clips on the outside of the insulation on one and the bare tube of the other to keep them vertical and from rattling.

If you drill out the holes in the manifold you may have to push a punch into the metal tubes to swell them out to make them fit tight. If you do not have a tight fit they will come out due to vibration from driving.

Cold air travels from the carb to the bottom of the manifold and hot air up to the carb fromon top of the manifold. The mesh is actually not required. I do not use it due to over time it breaks down and gets sucked into the choke assembly. I run without the mesh and the choke works fine.

Your shop manual should have a picture of this under the Fuel Section. I have a 66 and it is very well detailed in the shop manual.

Good luck.

Good luck.


I finally installed my autolite 4100 yesterday. Thanks all for the help with descriptions on the choke tubes. It worked out great.