Yamaha YZ250 2021, Owner'S Manual

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TIGHTENING TORQUES
2-8
EAM30203
ENGINE TIGHTENING TORQUES
TIP
 - marked portion shall be checked for torque tightening after break-in or before each race.
Item
Thread
size
Q’ty Tightening torques Remarks
Spark plug M14S 1 20 N·m (2.0 kgf·m, 15 lb·ft)
Cylinder head nut M8 6 25 N·m (2.5 kgf·m, 18 lb·ft)
Cylinder head stud bolt M8 6 13 N·m (1.3 kgf·m, 9.6 lb·ft)
Cylinder nut M10 4 42 N·m (4.2 kgf·m, 31 lb·ft)
Cylinder stud bolt M10 4 13 N·m (1.3 kgf·m, 9.6 lb·ft)
Power valve holder 2 M5 2 6 N·m (0.6 kgf·m, 4.4 lb·ft)
Link rod screw M5 2 6 N·m (0.6 kgf·m, 4.4 lb·ft)
Push rod bolt M5 1 4.5 N·m (0.45 kgf·m, 3.3 lb·ft)
Thrust plate screw M5 1 6 N·m (0.6 kgf·m, 4.4 lb·ft)
Side holder screw M5 4 4.0 N·m (0.40 kgf·m, 3.0 lb·ft)
Power valve link lever bolt M4 1 4.0 N·m (0.40 kgf·m, 3.0 lb·ft)
Pulley bolt M4 2 4.0 N·m (0.40 kgf·m, 3.0 lb·ft)
Power valve cover screw M5 4 4.0 N·m (0.40 kgf·m, 3.0 lb·ft)
Governor fork screw M4 2 5 N·m (0.5 kgf·m, 3.7 lb·ft)
Power valve housing bolt M5 4 4.5 N·m (0.45 kgf·m, 3.3 lb·ft)
Impeller M8 1 14 N·m (1.4 kgf·m, 10 lb·ft)
Water pump housing cover bolt M6 4 10 N·m (1.0 kgf·m, 7.4 lb·ft)
Coolant drain bolt M6 1 10 N·m (1.0 kgf·m, 7.4 lb·ft)
Radiator bolt M6 4 10 N·m (1.0 kgf·m, 7.4 lb·ft)
Radiator guard bolt M6 2 10 N·m (1.0 kgf·m, 7.4 lb·ft)
Radiator hose clamp M6 8 1.5 N·m (0.15 kgf·m, 1.1 lb·ft)
Air filter element M6 1 2.0 N·m (0.20 kgf·m, 1.5 lb·ft)
Carburetor joint bolt M6 5 10 N·m (1.0 kgf·m, 7.4 lb·ft)
Air filter case bolt M6 2 8 N·m (0.8 kgf·m, 5.9 lb·ft) 
Air filter guide clamp M5 1 3.5 N·m (0.35 kgf·m, 2.6 lb·ft)
Reed valve screw M3 4 1.0 N·m (0.10 kgf·m, 0.73 lb·ft)
Locknut (throttle cable handlebar
side)
M8 1 7 N·m (0.7 kgf·m, 5.2 lb·ft)
Locknut (throttle cable carburetor
side)
M6 1 4.0 N·m (0.40 kgf·m, 3.0 lb·ft)
Exhaust pipe bolt (front) M6 1 14 N·m (1.4 kgf·m, 10 lb·ft) 
Exhaust pipe bolt (rear) M6 1 12 N·m (1.2 kgf·m, 8.9 lb·ft) 
Exhaust pipe stay bolt (front) M8 1 25 N·m (2.5 kgf·m, 18 lb·ft) 
Exhaust pipe stay bolt (rear) M6 1 12 N·m (1.2 kgf·m, 8.9 lb·ft) 
LT