RE: YS140 Compression??
The compression will come up when you run it, but just for grins, pop the valve cover off and make sure the valves have .003" clearance on both the intake and exhaust. The factory sometimes gets them a tad too tight.
Leave the reg screw alone until you run it. If fuel flows from the carb when the tanks is pressured up, screw it in until the drip stops.