Yamaha XTZ 125K Owner's Manual page 54

2. Engine oil and filter replacement a. Warm up the engine for a few minutes.
b. Stop the engine. Place an oil pan under the engine and
remove the dipstick.
c. Remove the drain plug and drain the oil.
d. Reinstall the drain plug, check if the gasket is damaged
and lighten it to the specified torque.
Tightening torque:
Drain plug:
20 N.m (2.0 kgf.m, 14.5 lbf.t)
6-7