Well, I wish someone would have told me this when I first started with gassers. DO not use a stopper tank. This topic always creates an argument, but unless you like your plane full of raw gas, heed the warning.

Many will claim they have never had a failure, but if you have ethanol in your gas, no stopper will be compatible. Just be safe and use a fortitude , Bennett or Fiji water bottle style, screw on cap.

The general consensus on break in is to do it in the air. Glow engines gain cooling from the fuel, while gas engines do not as much. So they really require flying to stay cool. But then again, I have never bench run engines much. I prefer to do it all in the plane.

I have had a DLE 20 in my old Pica FW 190, and it has performed great. I run a 16-8.