Man I don't what to think...I'm pretty good setting up 4 strokes, but this thing has kicked my butt. I purchased the motor used, placed it on my engine stand set the low and high end. The motor sounds good and the low to high transition was great. With the throttle approx 1/4 stick I invert the motor the rpm starts climbing approx 2000 rpm and when i flip it back over the rpm lowers. If I try this at a idle the motor quits when inverted.

I thought the motor was lean so I adjusted the regulator richer, but I can't seem to get the regulator to rich. I've replaced the regulator and diaphram and still no luck. I've followed alot of the on-line help topics regarding this problem. It's defiantly a fuel delivery problem I just figure out the combination.

I was going to send it to YS Parts and Service, but they said, they only tune the motor straight up. Anyone have any ideas?