ORIGINAL: JoeAirPort

My DL-50 was doing this inverted (lean) and knife edge (rich). I'd start with the vent plumbed to a more quiet place. I had to put a velocity stack on my DL-50 to get rid of it 100%. When I got my 55 I just went ahead and did both mod's. Funny thing is they both run the same: Awesome. No changing of mixture no matter what I'm doing in the air. You can roll it from upright to inverted and the engine sounds identical. Same with knife edge both ways. It's very nice when the engine runs so consistent.

PS: Jody at ValleyviewRC helped me sort this out BTW. He has the v-stacks there.