Richard. I am glad you did tested the tank. I wonder that you get only 5 gallons out of it. Depending on your thanks construction, the overflow line might be bent down too far. It is usually the other way around.
Also you are stating "The sight gauge I have acts like it should be for a different sized tank. " I think you might be wrong here. The only Ercoupes that I saw with a float sticking all the way out when full were the ones that were using a different non cork float, like brass type floats. The cork sinks a bit into the level. because it is heavier. That way one is getting a more stable reading. When your float show full but is "only" half way up in the glass tube, this is the reading most people have with this type of fuel gauge. The point here is to be able to see when the float is getting higher - that would indicate a problem as well as when it is getting lower. Then "center tank seems to lose fuel volume ". The header tank empties itself out over the carburetor. If you got a Stromberg, it might leak slightly and that way you loose fuel. Close the header valve. If you have your plane parked outside, the fuel will expand over the course of the day and empty itself via the header tank overflow toward the wing tanks. Again , totally normal. What you are describing is what I experienced with my Ercoupe too. I guess this is just the way the Ercoupe work. You might look at the pictures here that show a tank apart. Although the one pictured is an older style, the same principle applies. http://www.ercoupe.info/?n=Main.HeaderTank Hartmut ----- Original Message ----- From: Richard Green To: [email protected] Sent: Sunday, October 12, 2008 5:45 AM Subject: [ercoupe-tech] Center Tank Fuel Thanks for everyone's help in my questions about center tank fuel feed. Yesterday I ran the engine long enough to fill the center tank (flew it) and the center tank fuel indicator came to rest around the mid- point in the new Skyport glass sight gauge. I then drained the fuel out of the center tank into a gas can (from the line to the gascolator)and it measured about 5 gallons (center tank looked empty afterwards). Assuming this is the max volume I get when running the engine I thought maybe my tank is just 5 gallons, although labeled as 6 gallons on the cowl. I checked the old log books and it says the tank was replaced around 2001 with a new tank from UNIVAIR. The part number shows it as an aluminm tank which is supposed to be 6 gallons. Still a little mystery in the volume question (5 or 6 gal capacity)but at least I get 5 gallons of feed rather than 3 or 4 as I feared at first when the gauge never went all the way up the sight glass when "full". Couple conclusions so far: fuel pump appears to be pumping and I get around 5 gallons. The sight gauge I have acts like it should be for a different sized tank. One other weird thing is that the center tank seems to lose fuel volume if the plane sits a few days unused (i.e., the sight glass level goes down with time). My mecahnic thinks it might be fuel going back through the fuel pump as it sits. Is there supposed to be a check valve in the system? Does that happen to all Coupes? Thanks again for your help. Rich Green N3881H 1947 415CD
