Fuel draw engine failure
 

Just a quick question to see if I am on the right track. Last weekend, I decided to pull my trainer off of the shelf to fly. I hadn't flown it since last November and wanted to make sure the engine was ready for the season. I flew 2 flights and in both instances the engine quit at with about 1/2 of a tank of fuel left. In checking I found fuel all along the fuselage, and on the engine. BTW: I am flying an Avistar with an OS46FX. Anyway, I had previously cut a hatch into the bottom of the fuse and when I opened it up the tank had fuel residue all over it. I pulled the tank, checked the clunk to see if it was bent 180*, looked at the tank, and each tube for leaks. Found the plug to be easy to turn in the tank so I tightened it back up. I suspect that fuel was being pushed between the fuel tank opening and the plug in the front and when I reached 1/2 way, the fuel was more likely to run out this way rather than into the fuel line. (BTW the engine ran beautifully until 1/2 full.) Is it possible that this is my only problem? I plan to fly it again to check, but just wondered if I should look at something else in the meantime.

Fuel draw engine failure
 

Check your lines for holes and also the foam around the tank. Might be getting bubbles when the level gets low causing it to suck air and quit. Also check the clunk and make sure it is where it is supposed to be and not against the front of the tank.

Fuel draw engine failure
 

Make sure the pick up line in the tank isn't cut either. It could be drawing air when the tank goes to half full.

Fuel draw engine failure
 

Flyboy/mscic - Have pulled the plug and looked at the pick up line, checked the lines for leakage and found all to be ok. Also on the bubbling, I don't think that is a problem cause I flew this plane all summer and fall last year and did not have this happen at all. That's really where I am at now. I did find fuel on the sides of the pug when I removed it, but that's probably what I should have suspected. However, I was able to twist the plug rather easily when I first did my check. I have since tightened up the plug, made sure the clunk is in the right place, and added a short piece of fuel line to the pressure line to the muffler. I think it might be fixed, but wanted other opinions of what I should check. Like I said, the only thing I haven't done is add foam around the tank.

Fuel draw engine failure
 

I'd say the leak caused your problems. Most likely when the fuel level got down to half, there was no longer enough muffler pressure in the tank to keep fuel going to the engine.

Fuel draw engine failure
 

Stick Jammer: That is what I suspected as well. With a full tank, the pressure was enough since there was enought fuel in the tank to keep up the pressure. Once the fuel level reached the leaky plug, the air pressure escaped through it. In both flights the fuel level that was left was just below the opening of the plug. I appreciate everyone's help on this one, you have given me what I needed. If the wx cooperates this weekend, I will test out my repairs. Just didn't want to leave anything unchecked. Thanks again.

Fuel draw engine failure
 

I was thinking the same thing too.

Fuel draw engine failure
 

the loose stopper in you tank was the problem , I had the same thing happen to me last weekend . When the stoppers start getting older they start to shrink and get hard and leak, it sure makes a mess inside the plane . Randy