Gas Tank and Glass Bowl not filling

[NW-FLORIDA]

8N- been sitting 8 years. I drained gas best I could from tank and carb. I put 2 gallons gas in tank, turned on full at sediment bowl and nothing. After taping on bowl with wrench it now drip 1 drop every 6 seconds.

1. How do I fix this issue?
2. If I have to drain the 2 gal of gas I put in it how do I do this?
3. Will float being stuck in carb cause gas not to leave tank into sediment bowl?

*Thanks for everyones help. I joined this forum years ago with my 850, now have it and this 8N. I am retired Air Force and some time to get dirty once again. Thank you all.

 

[Eman85]

remove the drain plug from the bottom of the carburetor and see how the fuel flow is, drain it into a pint jar and see how long it takes to fill it. How did you drain tank? There's a filter in the tank, one in the sediment bowl and one at the carb inlet.

 

[Mike Groom]

You need to remove the shutoff valve from the bottom of the tank, it just screws out after you remove the fuel line going to the carb. The screen or outlet tube is probably plugged in the tank. You need to siphon the gas out with a clear plastic hose so you can see the fuel coming out before you get it in your mouth unless you have some easier way to do it. There isn't a drain plug on the tank, I have screwed the valve out and used a funnel and a hose to a gas can but it can get messy. If you think you have a air lock remove the plug on the bottom of the float bowl or crack the line open to the carb, but I suspect you have blockage in the tank, you also should have the fill cap off to see if the vent on the top of the tank could be plugged.

 

[Mad Farmer]

Follow post #3. But first make sure the gas cap vents.

 

[Jim L WA]

N.W. If there is fuel in the carburetor bowl, then the float has the needle up into the seat and you won't see fuel coming into the glass sediment bowl until the float drops and opens the needle and seat. That's why Mike Groom wanted you to remove that plug.

 

[used red MN]

Follow post #3. But first make sure the gas cap vents.

Follow post #3. But first make sure the gas cap vents.

Mad Farmer, while you idea of the gas cap not venting is a legitimate concern here are some things to consider. If he only put 2 gallon of gas in the tank that leaves a considerable amount of air in the tank. So the air to liquid ratio is very high. Just as air compresses it also expands. It sounds like maybe he drained out a few tablespoons. At that point due to large amount of air in the tank the vacuum in the tank has changed very little towards the point where it requiring to be vented to displace the fuel leaving the tank. I would guess that he could easily drain a quart of fuel out before flow would stop or slow down. The fuller the tank is the lesser the amount of air in the tank. The quicker the non-vented cap would affect flow. Also in real world operation gasoline when heated and also when jostled around actual creates some pressure from vapor conversion. This is just food for thought. Yes, it is important to have a vented cap. But in this case a couple of tablespoons exiting the tank will be nowhere close to stopping fuel from leaving the tank.

 

[Caryc]

Mad Farmer, while you idea of the gas cap not venting is a legitimate concern here are some things to consider. If he only put 2 gallon of gas in the tank that leaves a considerable amount of air in the tank. So the air to liquid ratio is very high. Just as air compresses it also expands. It sounds like maybe he drained out a few tablespoons. At that point due to large amount of air in the tank the vacuum in the tank has changed very little towards the point where it requiring to be vented to displace the fuel leaving the tank. I would guess that he could easily drain a quart of fuel out before flow would stop or slow down. The fuller the tank is the lesser the amount of air in the tank. The quicker the non-vented cap would affect flow. Also in real world operation gasoline when heated and also when jostled around actual creates some pressure from vapor conversion. This is just food for thought. Yes, it is important to have a vented cap. But in this case a couple of tablespoons exiting the tank will be nowhere close to stopping fuel from leaving the tank.

Just remove the gas tank cap and try to start it and see if the gas flows.

 

[Tim PloughNman Daley RIP]

8N- been sitting 8 years. I drained gas best I could from tank and carb. I put 2 gallons gas in tank, turned on full at sediment bowl and nothing. After taping on bowl with wrench it now drip 1 drop every 6 seconds.

1. How do I fix this issue?
2. If I have to drain the 2 gal of gas I put in it how do I do this?
3. Will float being stuck in carb cause gas not to leave tank into sediment bowl?

*Thanks for everyones help. I joined this forum years ago with my 850, now have it and this 8N. I am retired Air Force and some time to get dirty once again. Thank you all.

Wow, setting for 8 years? Inside or outside? Have a battery float charger on it? Ran when parked? You have a vapor lock. 1st, the Sediment Bulb Valve gets opened to the 'OPEN 2 TURNS' mark on the knurled Valve Stem Knob, The 'FULL' setting opens the reserve flow inlet - the one on the bottom of Bulb with attached screen that goes up into gas tank and you don't see. 2nd, loosen Bulb top clamp and open Valve a tad. Gas should flow. No? Your system may have one or more obstructions. 3rd step is to perform the Fuel Flow Test with a cold engine. Pass? Carb seems to be working sufficiently. Fail? Begin the step by step problem solving method to determine the true root cause. Start at fuel tank and work downstream. The tractor fuel tank has a vent on the top. It gets plugged after 75+ years of working. It is not easy to get to and can only be cleared by removing the tank itself. It takes a minute to blow out the small vent hole on the dome but it is just a time consuming project doing so as the tank is bolted to the bottom of the hood and there are several other parts that need to removed first in order to get the hood & tank assembly off. In addition, the fuel tank itself will collect dirt, debris, rust, and chaf over years of normal usage. Total removal, boiling, cleaning, and coating of inside of tank is done by some but can be expensive. There are THREE filter screens in the fuel system. First is the internal one on the bottom of the Sediment Bulb. I advise not to just remove the Bulb until a last resort. The Bulb uses a 1/8" NPT male thread and the tank has the female end. Get the tank boogered up and it may be junk. The 2nd Filter Screen is the round, flat, fine mesh brass one that seals to the glass bowl. The 3rd Filter Screen is the one most forgotten or often neglected but the most important one when doing PM. This screen is soldered to the end of the Fuel Inlet brass elbow that screws into the Carb side. The APN-9194 Valve Stem is the only working part on the Bulb. It has a rubber seal on the shaft that will wear out and leak over time. Some new ones are cheap vinyl and fail even faster. It is an $8 part and is the only one you need when doing repairs. You do not need to buy an entire new Sediment Bulb Assembly. The Valve Stem comes with the knurled knob and the 8-32 screw and lockwasher that fastens it to the stem. Many knobs get lost in the field as they can loosen and fall off. Use dab of Threadlocking goop when putting a new stem on and that will never happen. When seal wears and its time for a new stem, you'll get a new knob as well. Finally, use the OEM 1/4" SS fuel line from Stem to Carb inlet. Fuel and brake lines use an industry standard special thread size. It is 7/16-24 UNS - Unified National Special. Never use anything else. Also never user rubber, copper, plastic, nylon, aluminum, or other material for the fuel line.

Tim Daley (MI)

 

[NW-FLORIDA]

You need to remove the shutoff valve from the bottom of the tank, it just screws out after you remove the fuel line going to the carb. The screen or outlet tube is probably plugged in the tank. You need to siphon the gas out with a clear plastic hose so you can see the fuel coming out before you get it in your mouth unless you have some easier way to do it. There isn't a drain plug on the tank, I have screwed the valve out and used a funnel and a hose to a gas can but it can get messy. If you think you have a air lock remove the plug on the bottom of the float bowl or crack the line open to the carb, but I suspect you have blockage in the tank, you also should have the fill cap off to see if the vent on the top of the tank could be plugged.

Thank you sir! I will get into it just as u say in the morning!

 

[NW-FLORIDA]

You need to remove the shutoff valve from the bottom of the tank, it just screws out after you remove the fuel line going to the carb. The screen or outlet tube is probably plugged in the tank. You need to siphon the gas out with a clear plastic hose so you can see the fuel coming out before you get it in your mouth unless you have some easier way to do it. There isn't a drain plug on the tank, I have screwed the valve out and used a funnel and a hose to a gas can but it can get messy. If you think you have a air lock remove the plug on the bottom of the float bowl or crack the line open to the carb, but I suspect you have blockage in the tank, you also should have the fill cap off to see if the vent on the top of the tank could be plugged.

Thank you sir! I will get into it just as u say in the morning

N.W. If there is fuel in the carburetor bowl, then the float has the needle up into the seat and you won't see fuel coming into the glass sediment bowl until the float drops and opens the needle and seat. That's why Mike Groom wanted you to remove that plug.

gas was dripping into sediment bowl very slow. Its full now.

 

[NW-FLORIDA]

Wow, setting for 8 years? Inside or outside? Have a battery float charger on it? Ran when parked? You have a vapor lock. 1st, the Sediment Bulb Valve gets opened to the 'OPEN 2 TURNS' mark on the knurled Valve Stem Knob, The 'FULL' setting opens the reserve flow inlet - the one on the bottom of Bulb with attached screen that goes up into gas tank and you don't see. 2nd, loosen Bulb top clamp and open Valve a tad. Gas should flow. No? Your system may have one or more obstructions. 3rd step is to perform the Fuel Flow Test with a cold engine. Pass? Carb seems to be working sufficiently. Fail? Begin the step by step problem solving method to determine the true root cause. Start at fuel tank and work downstream. The tractor fuel tank has a vent on the top. It gets plugged after 75+ years of working. It is not easy to get to and can only be cleared by removing the tank itself. It takes a minute to blow out the small vent hole on the dome but it is just a time consuming project doing so as the tank is bolted to the bottom of the hood and there are several other parts that need to removed first in order to get the hood & tank assembly off. In addition, the fuel tank itself will collect dirt, debris, rust, and chaf over years of normal usage. Total removal, boiling, cleaning, and coating of inside of tank is done by some but can be expensive. There are THREE filter screens in the fuel system. First is the internal one on the bottom of the Sediment Bulb. I advise not to just remove the Bulb until a last resort. The Bulb uses a 1/8" NPT male thread and the tank has the female end. Get the tank boogered up and it may be junk. The 2nd Filter Screen is the round, flat, fine mesh brass one that seals to the glass bowl. The 3rd Filter Screen is the one most forgotten or often neglected but the most important one when doing PM. This screen is soldered to the end of the Fuel Inlet brass elbow that screws into the Carb side. The APN-9194 Valve Stem is the only working part on the Bulb. It has a rubber seal on the shaft that will wear out and leak over time. Some new ones are cheap vinyl and fail even faster. It is an $8 part and is the only one you need when doing repairs. You do not need to buy an entire new Sediment Bulb Assembly. The Valve Stem comes with the knurled knob and the 8-32 screw and lockwasher that fastens it to the stem. Many knobs get lost in the field as they can loosen and fall off. Use dab of Threadlocking goop when putting a new stem on and that will never happen. When seal wears and its time for a new stem, you'll get a new knob as well. Finally, use the OEM 1/4" SS fuel line from Stem to Carb inlet. Fuel and brake lines use an industry standard special thread size. It is 7/16-24 UNS - Unified National Special. Never use anything else. Also never user rubber, copper, plastic, nylon, aluminum, or other material for the fuel line.

Tim Daley (MI)

Tim so great a reply. I will follow this post as gold and post results. I thank you!