The DLE 20 runs significantly better gapped at .025". I believe that Valley View recommends this number on the DLE 20s as well. A friend at the field had a DLE 20cc, that always missed from half throttle on up. It ran fine, but always missed. He had the ignition go bad, they replaced it, and it still missed occasionally. He chased the needles up and down with no luck in eliminating it. I asked him his plug gap, he said .020", just like they said. I told him to try .025" and you would not have believed the difference. It no longer missed, and he swore it had more power. It did sound like it was pulling harder, but that is a bit subjective.

This of course was on a real CM-6 plug, Stihl Ultra oil and 4 gallons of gas.