Is the carb adjustment screw on a Yamaha sh50 in or out to richen the mixture?

To richen the mixture on a Yamaha SH50, you should turn the carb adjustment screw out (counterclockwise). This allows more fuel to enter the mixture, resulting in a richer fuel-to-air ratio. Conversely, turning it in (clockwise) would lean out the mixture. Always make small adjustments and test the engine's performance after each change.