Six Pack Carburetor Binding?

[MoparHonda]

I removed all three carburetors from my 70 Plymouth Six-Pack for refurbishing. All went well, I put the front and center carburetors back on, no problems at all.

I can't get the back carburetor to work, it starts binding as soon as I tighten the bolts down. Both the manifold and carburetor base have been smoothed by a machine shop. I'm using the same Fel-Pro #60124 gasket for all three carburetors.

The carburetor does NOT bind if I torque it down without a gasket....

So, what is the problem and what is a good solution? Seems that using a thinner and possibly harder gasket may solve the problem? But, a thinner and harder gasket may introduce other problems?

 

[OH71RRunner]

Check the gasket against the bottom of the carb to make sure the blades (I really don't know what those are called) on the throttle shaft aren't catching on it.

 

[66Satellite47]

Check the gasket against the bottom of the carb to make sure the blades (I really don't know what those are called) on the throttle shaft aren't catching on it.

Doesn't take much of an offset to bind the throttle blades. Mis-adjustment on the blade to the shaft the carb on the manifold.

 

[MoparHonda]

Thank you, OH71Runner & 66Satellite, I've already checked the gasket and the blades are NOT catching on it. It turns freely until I get to a certain amount of torque on the bolts, then it starts binding, gets worse the more I torque the bolts.

Seems that tightening the bolts is causing the gasket to compress somewhat, which causes the base to twist slightly, which leads to the binding.

I was hoping to find someone who also had this issue and see how he solved it.

 

[pnora]

Take the front carb off and see if it fits on the rear of the manifold and if the rear carb will bolt on to the front of the manifold.

 

[OH71RRunner]

It could be possible that the gasket is getting squeezed just enough to push out allowing it touch the blades.

As pnora said above, swap the front carb to the rear, or swap the gaskets around between the 3.

 

[1 Wild R/T]

Seen this before on Sixpack end carbs.. The original gaskets were very thin... Thick gaskets allow the baseplate to flex...

 

[BSB67]

Seen this before on Sixpack end carbs.. The original gaskets were very thin... Thick gaskets allow the baseplate to flex...

This.

You can use a sealant on the gasket both sides then when you are assembling tighten slowly in small increments regularly checking the the shaft. When you start feeling a little drag on the shaft, stop tightening. Probably have done tis 10 times, never a leak.

Thinner gaskets are also suppose to be a solution, but never tried it.

 

[Fran Blacker]

Put a thin gasket on a xram adapter plate and throttle plates caught on adapter plate. Original gaskets are 3/32 thick.

 

[Jeff Erwin]

Those bolts don't have to be cranked down much, BSB67 has it right. When the carb starts to bind up, back off just a smidge (technical measure of torque), do that with each bolt. I have stripped a manifold tightening those too much so I have a bit of a mental thing about over tightening them. Extremely doubtful air can get through.

 

[66Satellite47]

I agree with Wild RT. The original gaskets were very thin. Never had a problem. I've seen some that are thicker and could be the problem. I used a very thin coat of grease on my thin gaskets too, keeps them softer also.

 

[WileERobby]

Yep... spot on, use thin gasket !

 

[mac]

https://www.forbbodiesonly.com/moparforum/threads/gaskets.99239/#post-910322727

go to the last post on this thread.