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Discussion Starter #1
After lots of investigation with timing, choke, float, mixture, etc I've got the car working great and starting great except for the usual hot start problem many others have. I discovered that on shut down with a warm engine the fuel boils in the bowl. BUT...the driver's side (and not the passenger side) venturi is allowing fuel to come out the little holes (not the squirter nozzles) and flood the car. I have no idea how to prevent this. Any ideas?
 

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Discussion Starter #3
It has a stock 1" spacer with the port on the back. The fuel isn't boiling over and I'm not sure if that is really the problem. The problem is the fuel coming out of the venturi...but I have no clue how it is happening. Are the issues related? Why only the one venturi?
 

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are you sure your needle and seat doesn't have any debris that is keeping it open?

i had a similar issue but mine would leak with the car on and continue to leak once off on my secondaries
 

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Discussion Starter #5
It appears to be sealing up fine from what I can tell. I rebuilt it just late last year. It will certainly make a mess if I press on the float!!

I just don't understand carbs enough to know how/why the one venturi would leak fuel and the other one doesn't.
 

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Confused

OK, you have me right where you want me...confused. In your first post you state it's boiling over. In your 2nd post you said is was not.

Because it's one side, check the needle seat. If that does not fix it, try the insulator.

What is your fuel pressure? Do you have a stock pump?

Dave
 

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Discussion Starter #7
LOL. Sorry about that. It is boiling but not boiling over. I'll double check the needle but I'm pretty sure it is good. Ya know...as I watched the fuel boil it seemed to only be when the bubbles bumped the float that I saw any fuel come out of the venturi. Interesting...

I don't know what the fuel pressure is, but I think it is plenty. I can make a mess with the gas if I want. I replaced the stock fuel pump about two months ago.

What sucks is this was never a problem before I got the engine rebuilt. I wonder if living at 7,000ft makes the fuel boil easier....hmmmm...
 

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Fuel boiling is a problem. Fix that first. A phenolic spacer will likely do the trick. If the problem still persists continue troubleshooting.

Jafo
 

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Discussion Starter #10
That's why car's vapor lock more at higher altitudes. But the question is Why only out the one venturi.
Exactly!

Fuel boiling is a problem. Fix that first. A phenolic spacer will likely do the trick. If the problem still persists continue troubleshooting.

Jafo
I looked for one but couldn't find one with the port out back. Even all the other threads I looked at didn't help. Could I add a 3/8" one to the stock spacer? I'm not sure if the mounting and air cleaner bolts are long enough though.
 

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Several options here.

Buy a 1" phenolic, drilll it, and put your own port in
Buy a 3/8" phenolic and stack it"
Replace your 2 paper gaskets with 3/16" spacer gaskets(one or both).
Buy a 1" phenolic spacer and hook whatever you have hooked into the factory spacer to a manifold vacuum tree instead.

And by the way living at 7000 feet does make fuel boil easier. Less atmospheric pressure=lower boiling point for all liquids.

Jafo
 

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what carburetor do you have?

pull out the needle and seat just to make sure there is no debris in there. Its simple to do. You will also have leaks if your needle and seat valve is not properly adjusted.

here is a how to vid: (not my video)

 

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ok i have a couple questions what the hell is a "venturi" you mean the little vent towers for the fuel bowl. and when you mean that the fuel is "boiling" you mean flooding the fuel bowl right which like i said before it comes out the vent holes/ well like everyone else said if these assumptions are true then yea your float is sticking. why is it coming out of one vent mabye they both dont go to the same place.
 

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Yep

are you sure your needle and seat doesn't have any debris that is keeping it open?

i had a similar issue but mine would leak with the car on and continue to leak once off on my secondaries

Had the exact same problem on a Volvo boat motor one time. Took out the the needle and cleaned the seat, needle, and needle bore with toothpaste and a pipe cleaner and it fixed it.
 

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I looked for one but couldn't find one with the port out back. Even all the other threads I looked at didn't help. Could I add a 3/8" one to the stock spacer? I'm not sure if the mounting and air cleaner bolts are long enough though.
You do not need to replace the existing 1" spacer with the port out the back. You will add another thin spacer that is phenolic or something similar that will not transmit heat. I used a multi-layer spacer that had a very thin gasket, then a thin sheet of aluminum, another thin gasket, another thin layer of aluminum. Total thickness was no more than 1/4". The gasket was the heat barrier and the aluminum acts like a radiator to dissapate the heat to the surronding air.

Dave
 

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I don't know what the fuel pressure is, but I think it is plenty.
If it's too much pressure, it can make it more difficult for the needle seat to seal against the higher pressure.

Dave
 

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Question to fuel boiling aside from carb issue, how is your fuel line run? Is it away from the heads, exhaust, block as much as possible? By the time it gets to the carb it maybe already to "warm".
 

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After lots of investigation with timing, choke, float, mixture, etc I've got the car working great and starting great except for the usual hot start problem many others have. I discovered that on shut down with a warm engine the fuel boils in the bowl. BUT...the driver's side (and not the passenger side) venturi is allowing fuel to come out the little holes (not the squirter nozzles) and flood the car. I have no idea how to prevent this. Any ideas?
Lower the float level.

As for leaking on dr side not pass, I bet it leans slightly that way.
 

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Discussion Starter #19
I will check the needle and seat, I may even have an extra set that I may use just to eliminate any issue.

I'll look into finding a thin phenolic spacer for stacking.

I already lowered the float in an attempt to solve the issue, but that just made the car run lean. It looks like the problem is the bubbling making the float bounce which allows fuel to get in. I'll work on solving the bubbling and move forward from there. The leaning is probably correct! The car has a slight lean towards the driver's side.

Anyone have any recommendations for finding a very thin spacer?
 
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