Fuel Tank - Sending Unit

[Mr Comet]

About two weeks ago I replaced my sending unit right after I ran out of gas. After changing out the sending unit for a new one I first returned about four gallons of gas. I am using an electric pump which in fitting is mounted about 4" from the outlet of the tank. Lower than the outlet fitting of the sending unit. When I attempted to pump the fuel out nothing was drawn from the tank. So I ran a 5/16" fuel line from the pump in fitting to a gas can mostly filled with gas. The results was every thing from the pump to he carburetor worked just as they were suppose to. over a couple of days I continued to fill the tank by gas can. Pump did not work. Today as I filled the tank with more gas from a gas can as I put in about 1.4 gal. about half the can, gas started leaking out the outlet spout of the tank (probably filled up to highest point of the tube of the sending unit). I reattach the 4" line to sending unit outlet and pump inlet, put another 1.4 gal. gas into tank. Tried the pump and no draw. Any ideas what I should try? Perhaps another 2.5 gal gas? some point all the air in tube of sending unit should be replaced with fuel right. Oh vacuum line is clear and cap is on.

[StarDiero75]

Could the sender be plugged somehow? I'd yank it and check it. If it works from pump to carb then its working. Sounds like the sender

[Mr Comet]

I thought that too, I have checked the sending unit and no plugs. It has to be 4" piece of pipe, sending unit, tank or vacuum.

[Mr Comet]

Without getting into all the details of what I did today, lets just say it's all working fine. I don't know what was wrong in the first place so I don't know what solved the issue. Since gravity was feeding the pump the only concern I have is when the gas tank level gets below the top of the sending unit tube. Will the vacuum of the gas kick in like when you syphon a tank?

[StarDiero75]

Without getting into all the details of what I did today, lets just say it's all working fine. I don't know what was wrong in the first place so I don't know what solved the issue. Since gravity was feeding the pump the only concern I have is when the gas tank level gets below the top of the sending unit tube. Will the vacuum of the gas kick in like when you syphon a tank?

If you have it hooked up and its working properly now, yeah the vacuum should keep it going

[Mr Comet]

I'll carry a gas can until I feel more secure.