RE: does changing oil mix change tune on DA-50?
Weren't you running the BelRay at 32:1? I'm guessing the diffrence wouldn't be as drastic (but would still exist) at 45-50:1. I am only jumping in because I just finished the 5th gallon on my DA-100 and am switching to H1R next tank... my tank's big enough... I'll kill the carbon!