Suzuki RM250 Owner's Service Manual page 50

Throttle stop screw
When the throttle stop screw is turned clockwise, the throttle
valve is forced upward allowing the engine to continue idling.
Throttle valve opening
After touching the throttle stop screw to the
Standard throttle valve, turn in the stop screw five to
six turns to raise the throttle valve.
Too high an engine idle may cause driveability failure
such as lack of engine braking and poor deceleration
during brake application.
CAUTION
MACHINE TUNING 4-5