fuel sediment cup question

[Astroguy]

hi I still have another question about my 1949 Ford 8N that I have owned since last december. it has been running flawlessly, I have plowed a little over a half acre plot, and I was discing yesterday when the engine sputtered.
I figured I should clean out the sediment bowl as I have noticed sediment swirling every time I open the fuel valve. I always wait for it to settle and then I start the tractor. but yesterday I was running over some very heavy soil clods as that field has not been plowed in over 25 years. I wondered if the bouncing caused the sediment bowl to allow some junk to the carb. the engine cleared itself in just a few seconds.
this morning I went out to clean out the settlement bowl for the first time. no problem about say a fifth of a teaspoon of sand like sediment. no problem.
I proceed to attach the bowl into place and proceed to tighten. then I turn on the valve and there is no gas flow. none whatsoever.
when I take off the clear sediment bowl and turn on the valve the gas flows very freely. when I put the sediment bowl back on the flow stops completely.
I did get the bowl to eventually fill up by loosening the sediment bowl tightening screw and letting gas flow over the sides of the bowl. I tightened it up and started the tractor and ran it for a couple of minutes and everything seems fine.
plus the gas valve is either soldered or welded into place so I cannot do much with it.
any ideas?

 

[Jim.ME]

If the carb bowl is full and the needle valve is sealing, gas will not flow until the needle opens when carb bowl needs fuel to hold the level.

It sounds like you need to clean your tank and likely the passage around the sediment bowl valve to get rid of that sediment.

 

[Jimmydog]

If the carb bowl is full and the needle valve is sealing, gas will not flow until the needle opens when carb bowl needs fuel to hold the level.

It sounds like you need to clean your tank and likely the passage around the sediment bowl valve to get rid of that sediment.

Jim, I took it to mean he couldn't get any gas in the bowl. Sounds like maybe air/vapor locked?? Seems like if the float seal is that stuck he's going to have problems with it later on too. Just thinking out loud.

 

[Tgrasher]

May I suggest that you put a shut off ball valve just before the carburetor. Easier to use and keeps your sediment bowl valve from wearing out. Pictured is a 1/8"nptf x 1/8" nptm ball valve.

 

[Jim.ME]

Jim, I took it to mean he couldn't get any gas in the bowl. Sounds like maybe air/vapor locked?? Seems like if the float seal is that stuck he's going to have problems with it later on too. Just thinking out loud.

With a properly sealed system, if the needle in the carb is closed, fuel will not flow into the sediment bowl from the tank. The fuel passage into the carb is supposed to be the only vent for air trapped inside the sediment bowl. The sediment bowl might fill slowly if air "burps" back up by the valve into the tank.

If the float is set right it will hold the needle seated, not allowing gas to flow into the carb until the fuel drops below the float set level. The needle would be stuck if the float had dropped and the needle did not open.

His description sounds like the system is working correctly, to me, given it started and ran. My thought is if he had started the engine after installing the sediment bowl, the engine would have used some gas, float would drop, needle open and the air would vent through the cab with the gas following into the carb bowl.

 

[used red MN]

Jim, I took it to mean he couldn't get any gas in the bowl. Sounds like maybe air/vapor locked?? Seems like if the float seal is that stuck he's going to have problems with it later on too. Just thinking out loud.

Jim in reply 2 is correct, there is no problem. Just as when you have a drinking straw or a clear tube with liquid then air, then liquid/air and you stop the flow with your finger on the end the bubble of air hold their position. The same is true here, the carb is full of gas and the float needle is closed. The trapped air in the sediment bowl cannot go anywhere until fuel is used out of the carb and the float valve opens to allow flow.

 

[soaked]

Agree, its not broke.
Wonder if the sputter was just momentary fuel starvation from gas at the bottom of the carb bowl bouncing away from the port leading into the jet.

 

[Astroguy]

With a properly sealed system, if the needle in the carb is closed, fuel will not flow into the sediment bowl from the tank. The fuel passage into the carb is supposed to be the only vent for air trapped inside the sediment bowl. The sediment bowl might fill slowly if air "burps" back up by the valve into the tank.

If the float is set right it will hold the needle seated, not allowing gas to flow into the carb until the fuel drops below the float set level. The needle would be stuck if the float had dropped and the needle did not open.

His description sounds like the system is working correctly, to me, given it started and ran. My thought is if he had started the engine after installing the sediment bowl, the engine would have used some gas, float would drop, needle open and the air would vent through the cab with the gas following into the carb bowl.

thank you for your input, this was what I was thinking and hoping.

I just needed some backup! thank you very much

 

[Astroguy]

Jim in reply 2 is correct, there is no problem. Just as when you have a drinking straw or a clear tube with liquid then air, then liquid/air and you stop the flow with your finger on the end the bubble of air hold their position. The same is true here, the carb is full of gas and the float needle is closed. The trapped air in the sediment bowl cannot go anywhere until fuel is used out of the carb and the float valve opens to allow flow.

thank you very much, I too was thinking exactly of the straw in fluid issue. I was a little freaked out but like I say she's running now and you guys are supporting normal operation. thank you

 

[flembo]

Had you just started the tractor the bowl would have then filled up on it's own. As others said no problem.

 

[Astroguy]

Agree, its not broke.
Wonder if the sputter was just momentary fuel starvation from gas at the bottom of the carb bowl bouncing away from the port leading into the jet.

thank you, normal operation is what I suspected and I appreciate the confirmation.
definitely I suppose you are correct about the fuel sloshing about in the carb, it was the first time in 5 months she ever sputtered and lost power, it was only for a few seconds .
this soil clods are so big it almost feels dangerous jumping over them.
thanks for the extra input

 

[Astroguy]

Had you just started the tractor the bowl would have then filled up on it's own. As others said no problem.

yes, surprising but sounds like if I hadn't even noticed that the ball would not immediately fall,it would have just ran fine. thank you

 

[Jim in LA]

My '51 started running rough yesterday while mowing, I stopped and adjusted the high speed needle and it cleared up for about 30 minutes. I put the tractor up and noticed some rust and crap at the bottom of the sediment bowl. I have not cleaned the tank on this tractor. It looked ok when I bought it and I have run it quite a bit. I removed the bowl and cleaned it up and inspected the bottom of the fuel valve/bowl assembly and discovered quite a bit of cruddy buildup on the big flat screen as well as the orifice that allows gas into the bowl so that as well as the tank probably need a good cleaning. I remember when I was in high school one day cultivating the soybeans with the '49 8N water had accumulated in the gas barrel and a bunch of it got pumped into the tank with the old time "chooger" pump, anybody remember those? I spent half the afternoon stopping at the end of every other row draining the water out of the sediment bowl. Not fun. Good ole days.

 

[soaked]

thank you, normal operation is what I suspected and I appreciate the confirmation.
definitely I suppose you are correct about the fuel sloshing about in the carb, it was the first time in 5 months she ever sputtered and lost power, it was only for a few seconds .
this soil clods are so big it almost feels dangerous jumping over them.
thanks for the extra input

Some clone carbs have an off road style needle that has a spring loaded ball on the non pointy end. Its ment to absorb shock from the float slamming the needle into it's seat in bumpy terrain.
Prolly don't need on a tractor...

 

[Jimmydog]

With a properly sealed system, if the needle in the carb is closed, fuel will not flow into the sediment bowl from the tank. The fuel passage into the carb is supposed to be the only vent for air trapped inside the sediment bowl. The sediment bowl might fill slowly if air "burps" back up by the valve into the tank.

If the float is set right it will hold the needle seated, not allowing gas to flow into the carb until the fuel drops below the float set level. The needle would be stuck if the float had dropped and the needle did not open.

His description sounds like the system is working correctly, to me, given it started and ran. My thought is if he had started the engine after installing the sediment bowl, the engine would have used some gas, float would drop, needle open and the air would vent through the cab with the gas following into the carb bowl.

I guess we were saying the same thing, except I was thinking his carb bowl was empty. ergo stuck needle valve. I guess shut would be the correct term in this case. Good call.

 

[560Dennis]

Does not look like a strainer set up for inlet to carburetor. Suggest replace with one .

 

[used red MN]

Does not look like a strainer set up for inlet to carburetor. Suggest replace with one .

Dennis, don’t know what you’re looking at Astroguy the original poster didn’t post any photos? Are you looking at Tgrashers photo in reply 4?

 

[560Dennis]

Also the sediment bowl shows an inlet strainer. Would suggest getting one after when you have that the tank flushed .
YT offer these for 8 n as example

 

[da.bees]

If your biggest concern about your 75 year old tractor is a momentary sputter, you should parish the thought and do a happy dance all the way around it.

 

[paul]

Sounds like the whole system is working perfectly and you refilled the sediment bulb exactly as it should be done.

No problem to solve here.

Paul