Sticking Needle Valve

John Gibson

John Gibson

Senior Member
If I leave my all stock 36 for more than a few days the gas will evaporate from the Stromberg 97 bowl. The needle valve will stick shut when the float drops from the fuel evaporation. Consequently the engine will not start because no fuel can get into the carburetor. My fix is to disconnect the fuel line on the carburetor side and remove the brass fitting from the carburetor. I then pull the needle valve out and put it back in, reassemble everything, squirt a shot of petrol in the carb and she starts right up. I remember fifty years ago there was a shoulder on the back of the needle valve with a wire attaching it to the float which prevented this issue. What am I missing on this puzzle?
Thanks,
John
 
The issue is you have a fibrous needle valve rather than the original metallic needle valve. Modern fuel will make that valve stick as you have experienced. You’ll need to change it out for a correct original type valve, which will also require a re-setting if your float. You’ll have no sticky float valve after this task is completed.
 
Electric fuel pumps solve many issues but I am not sure if it would push out a stuck needle. How about sanding/filing the skinny beveled sides of the needle in between the larger flats slightly to make it fit slightly looser and able to be pushed past by a regular or supplemental electric fuel pump.


I do know what you are talking about with the needle return wire clip, the carbs on my lawn equipment have them. Possibly try a full service lawn equipment store and see if they have one that would be a match up?
 
if my fuel was leaking out of my float bowl that quickly i'd be looking for evidence of leakage around the base of the carb or possibly out of a crack in the body of the carb itself. and i'd also be checking my oil for the dilution from the gasoline.

in addition the sticking needle in the floatbowl would lead me to believe that the needle and seat need replacing. :)
 
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I only use marine gas in both the 33 & 36. No issues with the 33 and I’m running a Stromberg 97 on the 33 with a two to one adapter. Fuel pump on the 36 is a later one with the glass bowl which looks to be full all the time. Fuel pump pressure is in the 2 1/2 to 3 pound range. Fuel pump on the 33 is the 32/33 only variety.
 
I had a float needle that was a sticker. In the up position. Sometimes no start when I came out of the store. Open hood, very light tap with small brass hammer. That got old. I polished the sides of the needle with fine steel wool, helped some. I cannot get non ethanol gas easily here. I had quit the use of marvel mystery oil as it's 9.00 a qt here and I'm trying to retire. Well, I went back to the mmo and the problem is completely gone. I feel it has other benefits as well.
 
You could also try polishing the needle with tooth paste or other fine compound. It helps in leaky situations, maybe sticky situations too. Clamp the needle in a drill, and run it with paste on a cotton cloth. worth a try anyway
 
I have the same problem with my 66 GT-350, it sits for a long time and the needle and seat sticks closed. I can tap on the carb above the seat, and it will drop open and then it will finally get gas into the carb. The rubber tipped needle and seats are the worse, but the metal ones can stick to. When I was mechanic, we had 400 vehicles all with carbs in the fleet. Some of the vehicles would sit for a long time and the same thing happened to them. The accelerator pumps on carbs can also dry out and get hard and then you get a hesitation. Carburetors do not like to dry out. They have an open vent to the atmosphere, so the fuel eventually evaporates. The best thing is to start them once a week before the fuel dries up in the bowl. I can let a fuel injected car sit for months and it will fire right up; I can't do that with a carburetor.
 
Nobody has ever seen carburetors with little dents all over their float bowls, right? Kinda like tap-tap-tap with the handle of a wrench?

Edit: Oh-oh. GB and Flathead, I plead guilty to not reading the latest posts before posting my own thoughts. My mother kept a small stick under her driver’s seat. No dents on her carburetor!
 
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ford38v8 said:
Nobody has ever seen carburetors with little dents all over their float bowls, right? Kinda like tap-tap-tap with the handle of a wrench?

Edit: Oh-oh. GB and Flathead, I plead guilty to not reading the latest posts before posting my own thoughts. My mother kept a small stick under her driver’s seat. No dents on her carburetor!
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I know others have claimed to have had issues with the "new" Stromberg grose type of valve, but I've had nothing but trouble free usage with these. Maybe worthwhile looking into into if you can't get your set up to free up.
 
There is no shoulder on the needle and no clip from the float to the needle, never was on the Stromberg. Needle should be all steel and not brass, triangular shaped body with rounded end at the float. the brass fitting should be either stamped .098 OR have a slight groove machined around the end at the fuel line fitting.
 
Tim Ayers said:
I know others have claimed to have had issues with the "new" Stromberg grose type of valve, but I've had nothing but trouble free usage with these. Maybe worthwhile looking into into if you can't get your set up to free up.
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Oh man, I have had a few of those in client's vehicles that stuck in the closed position.
 
John Gibson said:
Needle is all steel, triangular shaped with a rounded end. Brass fitting has the machined grove.
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I wonder if that's the needle that should be placed in the bottom of the carb and NOT the top cover.
They appear nearly identical but are not interchangeable.
Do you have another needle / seat you could swap?
 
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