If you are running a 3 line system and the clunk fell off. I have a couple of questions.

After you fueled up did you see the fuel running out your vent line? Are you sure that during your routine that the vent line did not contact the muffler and seal itself closed? If it did the engine will go lean and start collapsing the fuel tank. It is possible that the clunk tygon tubing shrunk as well and allowed the clunk to fall off.

It is always a good idea to safety wire or use tye wraps for your fuel connections. I had this exact scenario happen to me on my maiden last year. The tygon tubing contacted the muffler and sealed itself closed. Upon landing the engine was of course hot and spinner as well, You would be amazed at how small a fuel tank can get under vacuum.

Check your lines and then recheck you needles. I have my DLE-55 running a tad rich on idle. You can see smoke at idle. When going from idle to full throttle I have my high end adjusted to where it will transition from idle to high speed with no hesitation and no lag. I like mine to be just a little rich during the hot summer here in Texas but not so rich where performance is affected.

Good luck and keep us posted of your findings.

Regards
GlennWilliams