Technical HELP Chevrolet 283 2bbl Rochester carb squirts fuel!!

Hello everyone,
My brothers 62 Chevy with a 283 V8 Rochester 2 barrel was running great up until a few days ago when he went to fire it up and a stream of fuel shoots out of the below circled tube on the top of the carb!! A literal stream that shoots straight to the firewall! I have never seen this before.
Does anyone have any idea why?
Does he need to replace carb or rebuild it?
Is it something else?

Thank you!!

 

My first thoughts are either the needle/seat stuck open, the float could be full of fuel, or too high fuel pressure. Then again it could be something else.

 

^^^^^ X2 on one and two listed. Check those first since it ran fine before.

 

Tap the top of the carb with your hammer. See if that fixes it. If not something is in the seat, holding the needle open, or the float has developed a hole in it. But try the hammer first

 

^^^^^ BFH or lfh?

 

Id start with the lfh, then titrate hammer size to the required BAM!

 

The tubing you have circled in red is a fuel bowl vent. Gas coming out there means your fuel bowl is over-full. The help from TCATTC, Johnny, and Lloyd's are various tactics to cure the cause.

 

We used to pinch off the rubber hose before the fuel pump and run the engine until it ran out of gas. Doing this allowed the needle to drop really far from the seat and when the fuel hose was unpinched and engine restarted the sudden inrush of gas would flush out any dirt.

 

^^^^^ and possibly a hammer.

Lynn

 

Soooo , is tapping with a hammer or squeezing the fuel line the right way to repair it , or would the OP be better off cleaning & rebuilding the carb & servicing the fuel system ? I know how all of you only approve of doing things the " right" way

 

I'm amazed ...

 

You can try the band aid methods but I'd suggest pulling the carb off, taking it apart and checking the float and needle and seat to see exactly what is going on.

That carb should have a brass float and they can get a hole in them and fill up with gas and sink. A new float and kit won't cost much over 20.00.

First I'd pull the fuel line out of the carb and pull the fitting that it screws into and see if there is actually a filter in the carb. I've seen too many cars and trucks that the filter in the carb plugged up and someone pulled it out and never replaced it.
Then run a hose from the fuel line to a gas jug and fire the car up and run it until it runs out of gas as others suggested before putting a new filter in and trying it again . If that doesn't work pull the carb off and go though it.

I always put a filter between the tank and the fuel pump on all of my older rigs simply because old tanks very often have dirt and crud in them that ends up breaking loose and plugging things up. You might plug the filter up but you don't kill the fuel pump or plug the carb. After going off and leaving my gas cap for my 48 on the gas pump at Grand Teton national park before driving through Yellowstone and then driving on fresh chip seal for 20 miles and then having my fuel pump crap out at the top of the Continental divide and coasting down to Whitehorse Where I bought a fuel pump from a kid going in the Navy the next week I don't want another dead fuel pump.

 

Tried the hammer method already and same results, thank you for the suggestions though.

 

Good information, thank you!

 

UPDATE:
We tried all of your suggestions, I really appreciate the input, but nothing worked.
I think what happened is we flooded the bowl by pouring gasoline into the bowl vent pipe to get it started up.
Is it possible that we drowned the float???

Once again thanks a lot fellas!

 

Besides the dirt thing...fairly common for some float needles to get slightly cocked and stuck when the float bowl is empty, causing this problem. Usually a rap on the top of the carb near the fuel inlet will jostle the needle enough to get it free. If that doesn't work then it's time to pop the top off the carb and see what ya got.
Good luck!

 

No. The float is designed to live in a bowl full of gas and pouring more gas on top of it will not “drown” it.

 

stock mechanical fuel pumps put out about 5 - 6 psi. The needle and seat / float are not designed to seat off properly with more pressure.

 

Trying to sift through possibilities:

"Was running great until a few days ago" - this probably eliminates too high fuel pressure

So as mentioned by several: (1) debris in fuel valve, (2) damaged float

Carb should come apart and the float tested.

Assuming it is an original brass float (if not a brass float, replace it with a brass float), the original brass float may be tested.

If the float does not have liquid when you remove the float, fill your sink with as water as hot as the hot water heater will deliver. Now submerge the float. The hot water will pressurize the air inside the float. If there is a leak, the leak will blow a stream of bubbles like an innertube (showing my age here) with a nail in it.

If the float is bad: Current new floats from 12000 miles away are assembled with some type of something (I hesitate to call it solder) that will FAIL if placed in ethanol fuel. A tested float from a junkyard carb, or, if you can find one, a new old stock float would be the way to go. If you ignore this paragraph, and order a brand new float, would suggest you order a case of them, plus several airhorn gaskets so you can change as needed.

And for those that suggested the hammer (large or small), you are ALL hereby awarded the "Dr. Goodpliers award" (named for the evil twin of Mr. Goodwrench)!

Tapping the carb with the PLASTIC handle of a screwdriver will sometimes dislodge a stuck float. A better method is to (as the OP tried) fill the fuel bowl through the vent with fresh fuel. Float buoyancy will dislodge it, with no physical damage.

Jon.

 

How much fuel pressure does it take to overfill a carb and squirt the gas on the firewall from the bowl vent?

 

Probably fan is blowing the gas to firewall.

Sent from my LG-TP450 using The H.A.M.B. mobile app

 

"A literal stream that shoots straight to the firewall". His words not mine. Lippy

 

When I read that I found it funny and concerning at the same time. All I could see in my mind is a novice ending up like a child with a...

 

It’s not a difficult carb to remove and take apart and see what’s inside the bowl. If there is junk in the bowl, getting the needle to seat now, doesn’t give me an easy feeling driving it somewhere.

 

I did NOT replace the needle and seat YET, they have been ordered will arrive in a couple days.
You think that's it?