When to shut off fuel

[1crosscut]

Originally Posted by Licensed to kill

What would be the point of running the bowl empty?. To my way of thinking there is no way fuel can leak once the valve is closed and there isn't anything in the bowl that could be negatively affected by fuel sitting in there, even for extended periods so, why run it dry?.

Every once in a while on hot days after shutting off the engine and then restarting a short time later I have had some rough running issues for a minute or two. I figured what was happening was the fuel in the bowl and first bit of fuel line got hot due to no air flow / fuel flow and perhaps boiled causing the temporary running issue. Now I shut off the fuel and let it run for a bit when stopping for short times on hot days. This allows fresh "cold" fuel run into the carburetor for trouble free restarts.

I always shut the fuel valve off and let it run dry when parking over night etc...

[1929]

Originally Posted by johnbuckley

I turn if off about 20 seconds before I switch the ignition off

x-2

[California Travieso]

Originally Posted by Licensed to kill

What would be the point of running the bowl empty?. To my way of thinking there is no way fuel can leak once the valve is closed and there isn't anything in the bowl that could be negatively affected by fuel sitting in there, even for extended periods so, why run it dry?.

The first time I brought our new (to us) A Roadster I parked it in our attached garage without shutting the fuel valve off. The next morning my wife complained about "the awful gas smell" in the garage. I checked the floor and the carb and couldn't find any leaks. She said "I don't care get it out of the garage."

One of the guys in our club suggested I turn off the fuel shut off valve and let it run until it ran dry. I did it and no more gas smell in garage! Bonus, no more unhappy wife!

David Serrano

[HoarseWhisperer]

I always shut the fuel off as an added safety measure, but no longer run the carb dry due to flash rusting inside the bowl.

[denis4x4]

Turn off the gas and battery every time I pull into the shop. Using ethanol free gas, so I’m not concerned about leaving gas in the carb

[1928Mik]

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I will let the engine die cause the needle valve will stick closed on occasion otherwise. I also like the safety feature along with disconnecting battery.

[Keith True]

I just parked my 30 roadster for the winter.I poured in some
stabil,drove the car to a place I own three miles away,and backed it in the shed.I pulled the fuse out,shut the gas off,and slid a pan under the front of the engine.Next May or so I will put the fuse in,pour the anti-freeze that dripped out of the water pump back in the radiator,start it up and drive it away.In the spring I will pretty much run the tank to empty before I add fresh gas.I use the older 2 ball Grose valves,I have no problems with them sticking.

[NCRebel]

I had been turning the fuel valve off as I shut down the engine. However, I lean toward starving the carb bowl before shutting down. The heat of the deep south will create fumes in the garage. Anyway to reduce that problem sounds good to me.

[1930-Pickup]

On aircraft equipped with reciprocating engines, the pilot closes the fuel valve and then waits a few seconds for the engine to die. There are several advantages to this FAA recommended procedure. If my Model A shut-off valve worked properly, I would do it that way too

[ccb360]

Switch off the battery and shut off fuel valve (run carb dry) every time I park the vehicle in a structure in which I sleep.

[heneste]

I shut it off and then let the car die from lack of fuel flow. I figure it avoids residual gas from gumming up the jets and the carb if I don't run the car again soon. It's also a good habit for me so I don't have the shutoff valve seize in the open position from lack of use.

[holdover]

"Turn off the gas and battery every time I pull into the shop. Using ethanol free gas, so I’m not concerned about leaving gas in the carb"


Ditto Do same, same

[glenn in camino]

I turn mine off after I'm in the garage, I also place a plastic bucket under the carburetor in case of leaks.

[Chuck Sea/Tac]

Originally Posted by Licensed to kill

What would be the point of running the bowl empty?. To my way of thinking there is no way fuel can leak once the valve is closed and there isn't anything in the bowl that could be negatively affected by fuel sitting in there, even for extended periods so, why run it dry?.

Revist how a carbs work. There is a float valve , that can leak and will overflow the bowl and run out on the floor. I usually only shut mine late 31 valve off at night.

[Dollar Bill]

Originally Posted by Dick Steinkamp

The "Instruction Book" makes no mention of the fuel shut off valve. I would think that if it was important to turn it off every time you stopped that it would be mentioned.

Henry moved the valve under the hood in May of 1931. I doubt if the owners opened the hood and shut off the valve every time the car was stopped.

I guess it doesn't hurt to do it...unless it wears the valve out quicker. How often to we check the valve to insure it is actually turning off the fuel?

Good observation Dick. My guess is the original parts were better quality, they were at least newer

Henry must have thought the valve was needed or he would have omitted it?

Each time you run the fuel out of the bowl it creates an air gap in the glass sediment bulb. You can check for this air gap to ensure the valve is holding.

[smittykid]

Originally Posted by 1928Mik

Like Dollar Bill says. I turn valve and let the engine die, then shut key off. No fuel in bowl, no chance of leakage in garage.

Just make sure your valve under the tank isn't leaking. On one of my Tudors I would shut the gas valve off & let it run till it quit. Next morning I would still smell gas in the garage. Turns out the valve had a very small leak. I bought a valve rebuild kit just to find out that the repop gas valves can't be rebuilt-just the originals(or so I've been told). Got a new repop gas valve-problem solved.

[Licensed to kill]

Originally Posted by Chuck Sea/Tac

Revist how a carbs work. There is a float valve , that can leak and will overflow the bowl and run out on the floor. I usually only shut mine late 31 valve off at night.

My question was not about shutting the valve off, it was about running the bowl empty after closing it. Once the valve is closed, no fuel can leak even if the bowl is full so there is no need to run the bowl empty to prevent the possibility of leaking. That's why I asked what other reason there was.

[Dick Steinkamp]

Originally Posted by Dollar Bill

Henry must have thought the valve was needed or he would have omitted it?

A shut off valve is necessary to service or repair anything downstream from the fuel tank (fuel lines, fuel filter, and carb).

It's a bonus that it is there for us if we have a suspect needle and seat in the carb.

[26 Coupe]

There is another potential safety hazard no one has mentioned yet. If you are using an aircleaner with a paper filter that is below the carburetor throat, a leaking needle valve can allow gas to soak the filter. If you have a backfire occur, it can start a sizable fire in the engine compartment. The previous owner of my roadster had it happen to him. He was lucky that it only blistered some paint.

[steve s]

I shut the valve just before pulling into the garage. I don't attempt to run the carb dry; I just want to lower the level in the carb bowl to allow for expansion as heat soaks out from the block after shut down.