Fuel Tank - Residual Capacity

[Randy Webb]

Anybody happen to know how much fuel is left in the tank after you run it out? i.e. pump as much fuel as possible out with the fuel pump?
('73.5 with CIS pump)

- ANd would opening the bung on th buottom of the tank let all that residual out?
(Assuming I didn't tear the thing up trying to get it out)

[RoninLB]

Originally posted by Randy Webb

Anybody happen to know how much fuel is left in the tank after you run it out? i.e. pump as much fuel as possible out with the fuel pump?
('73.5 with CIS pump)

- ANd would opening the bung on th buottom of the tank let all that residual out?
(Assuming I didn't tear the thing up trying to get it out)

Hello Randy.. That fuel tank screen does get beat up after awhile.. I guess, generally, you might want to just get a new one if it has over 100k mi on it.

I used a 1/2 hose and attached some weight to the end to keep the tip low when I put it inside the tank thru the fuel gauge hole. I used a flashlite to see inside with the gas gauge sender removed so I'm sure the hose is laying low. Then I raised the whole car up evenly to create a bigger head differential when I began sucking to create a siphon. Todays gas isn't as bad as the old stuff which tasted like sucking on a big lemon. Actually no lingering after tingle taste with a water rinse of your mouth nowadays.

Then I dropped the bung cap and drained the remainder Pint of gas. I've never used the fuel pump to drain so I can't give you hard info., but imo the routine fuel pump pick-up is/was about 1in off the bottom. The general consesus is/was that you have 10% Less useable fuel than the complete capacity of the tank.

When your removing the bung drain cap any gas will tend to flow down your arm.. so maybe position your arm with that in mind.

[Randy Webb]

Thx, Ron - Uhh gas is full of benzene a real nasty carcinogen (also a teratogen, mutagen, and .... just use a pump eh).

Usng the 10% figure - I think 90% fresh gas will be fine - I ws getting out the old gas from having the car sitting so long. Was curious about how much was left. inspected the screen a couple year ago when I was checking the tank for rust - it seemed fine , but maybe I should have just replaced it. Next time I will.

[RoninLB]

Originally posted by Randy Webb


inspected the screen a couple year ago when I was checking the tank for rust - it seemed fine , but maybe I should have just replaced it. Next time I will.

who knows. I read and saw some screens that detorated over time. and the time varied.. I did the squeeze fingers touchie feelie on my old one and it seemed fine, but i already had a new one.. so now I keep it in my big ride storage section.