You are rich on the low end and may be slightly rich on the high end. This is a very common issue on the DA50, they do not like to be rich. Lean out the high needle for max RPM, then richen (drop max RPM by 250) .. tune the low needle until rapid transition from idle to WOT just creates a stumble.... once you feel the stumble.. open the low end needle literally one screwdriver blad width at a time until the stumble just goes away.. it will solve the problem.

The other thing is that this annoying trait is more likely to happen with petrolem oil and during break in than it is on synthetic oil and after its run a few gallons. I have 3 DA50s, they all did this.. carb mod or not.. but once leaned and once on Synthetic.... never once. Best running engines I have ever owned, in fact, once I get them running perfectly I have not touched the needles... one DA50 I have is 2 years old and 300 flights .. never touch it.

Run them as lean as you possibly can on the low end and switch over to BelRay H1R at 50:1 after one gallon... you'll never see the problem again.

DP