Britton,

I flew my DA50 the first couple flights with the factory settings and received 'I did not know DA made a four stroke' comments from the guys at the field. I leaned the low speed needle about 1/2 turn and the engine smoothed out and sounds great and has a ton more power. No more four stroke gurgling. That is probably the ruff sound you are hearing on yours.

Check out [link=http://tech.flygsw.org/walbro_tuneup.htm]Walbro Carb TUNE UP & Illustrated Guide[/link] for a methodical approach to setting the needles. Then do as DA recommends and made it 'slightly rich'. Whatever that is.

Stan