How much transmission oil does a 2001 Yamaha YZ 125 take?

to fill transmission oil to proper amount simply unscrew the "fill Screw" which is on the right side clutch cover and start filling oil (with bike straight up). Once oil starts coming out fill screw stop filling and catch oil until it stops coming out. replace screw and your set to go.

THIS PROCEDURE WILL WORK FOR ALL 2-STROKE BIKES THAT I KNOW OF.

Hope this helps.