A 19 pound plane is about 20 pounds with fuel assuming a 16 oz tank. The thrust off a DA50 with a pitts muffler is about 26 pounds (max) from actual measurments that people have done with digital fish scales. So you have nothing near a 2:1, closer to 1.25:1. That's why it's sluggish to pull out of a hover. Get it down to 15 pounds and you're talking a whole different story.

Also you need to fully break in the DA 50, use a less restrictive muffler, and tune it properly to get all that power.