1985-1986 Honda ATC250R Shop Manual, Page 198Get this manual
HYDRAULIC DISC BRAKES FRONT
1Squeeze the brake lever (or depress the brake pedal)open the bleed valve 12 turn and then close the valve
BLEED VALVE
Do not release the brake lever (or pedal) until the bleed valve has been closed
2Release the brake lever (or pedal) slowly and
wait several seconds after it reaches the end of its travelRepeat steps and until bubbles cease to appear in the fluid coming out of the bleeder valveTighten the bleed valve