I have run a search to find info about startup tanks. I came across an interesting suggestion that, instead of having a clunk line inside, if you feed from the bottom of the tank then you can flip it upside down to clear the lines before disconnecting. This sounds like a very good idea to me.

The question I have regards the overflow tank vent using this method. If this is at the top of the tank then all is fine during normal operation. When you flip the tank upside down prior to disconnection the vent will now be placed at the bottom of the fuel (I am assuming a pipe vent similar to a regular glow tank rather than a hole). Will this cause excessive restriction or will the tank still vent ok through the fuel? (I hope that make sense).

Are there any other methods people use to limit the amount of fuel coming out of the tube after disconnection?

If you disconnect your overflow tank while the tank is sitting on the ground, versus while the tank is elsewhere (say sitting on your wing) you will minimize the amount of fuel coming out of the overflow tank - the fuel line will want to drain back into the tank.

I do what Ron suggests. It minimizes it. Also, I always wear rubber gloves when I messing with fuel. I rubbed my eyes once while flying had fuel on my fingers. It burns and I blew the gear out of my airplane on landing, and at the time didn't care just wanted to be able to take my jet home. It hurt.

I bend the tube down to the bottom, front of the tank and the vent to the top front of your start up tank. Just before disconnecting it stand the tank up on the ground, this way both lines are not in the fuel.

John

Yes, pinch the pipe between thumb/forefinger nails close to the disconnect point! ;-)

Most guys have the vent coming out of the bottom of the plane. When you disconnect it some residual fuel in the line comes out. I put my vents coming out the side of the fuse as close to the bottom as I can get. Since the vent line is horizontal and there is a slight suction on it no fuel or never more than a drop comes out when you disconnect, and even if some does your hand isn't under it.

Another good reason to put the vent on the side is if you ever have to do gear up landing you won't rip it out of the fuse.

Also I always place the overflow tank on the ground before disconnecting.

Joe

I was a firm believer in side mounted vents, however, fuel tends to get sucked out in flight, and makes a heck of a mess / stains on the airframe...they are both on the bottom now....

I stand my tank on end on the ground before disconnecting....

That's never been a problem. My vents are a short piece of brass tubing. I cut a 45 degree bevel on the end, facing forward. That way there is always a positive pressure on the vent whenever the plane is moving forward. It also puts a slight positive pressure in the tank, making life easier on the pump.

Joe

tried that and it worked except now I had this pointed spear sticking out the side of the fuse. The blood made more of a mess than the fuel did...........

Just pop for an extra few bucks and put a stopcock valve on the overflow line-turn off stopcock, unplug line very little if any leakage. Scott

Sorry to hear that. I go over mine with fine sandpaper to round off the end and eliminate any sharp edges. Also I keep a red plastic cover on them when not flying; not so much for protection but to keep any fuel from dribbling out when loading/unloading or carrying the plane up the from the basement.

Joe

Well, it wasn't quite as bad as I made out, but I have a smoke system on board as well, so need two vents. (that smoke oil is really messy when it overflows.) It just worked out far better for me to have them both on the belly.......