Thought I would put this here as it has to do with a clunk per se. I thought it would be prudent to re-plumb my fuel tank as the yellow gas line was hard and not floating to the bottom as I would like it. I grabbed some line from the supply hanging on the wall and promptly re did the tank. Went to the field and flew for about 5 minutes when the engine flamed out Needless to say I didn't make it back to the landing area. I was lucky. The grass was high where I landed and the ground was soft. What the he..? Was the low end too lean?, did the ignition die? Pancaked it and did a little damage, nothing serious thankfully. I am taking the fuel out of the tank while wondering what happened and I can't get anything out of the tank Long story short, the fuel line I used to plumb the clunk is a larger ID that the other line I have. It actually slipped off of the stopper and the engine could suck no fuel. Dag! The fuel line that has worked fine forever has writing on it that says, "GO 1480." This may be old hat to you guys, but it almost cost me a 35% plane for my ignorance. I now have the stainless wires on the tank lines and make sure the gas lines say "GO 1480"