We tried leaning the low speed and got it low enough that it died on the throttle advance. Then we bumped it up until it responded properly. Then we leaned the top end until it sagged after a few seconds at full throttle. Then we opened it up until that smoothed out. BTW My helper is an experienced giant scale flyer. He is familiar with the tuning. I also put a tube on the carb hole and ran it into the fuselage. The way it is blowing burnt oil, I'm wondering if it just doesn't need more break-in . I've had several gassers but this is the first one that didn't at least run reasonably smooth when first run. This is also the first non name brand motor I've had. My other are Taurus, 3W, ZDZ, Quadra.