Engine Specifications - Yamaha YZ125 2022 Owner's Service Manual

EAM20128

ENGINE SPECIFICATIONS

Engine
Combustion cycle
Cooling system
Induction system
Displacement
Number of cylinders
Bore  stroke
Compression ratio
Starting system
Fuel
Recommended fuel
Fuel tank capacity
Engine oil
Recommended brand
Lubrication system
Engine oil
Premix ratio
Transmission oil
Type
Quantity (disassembled)
Quantity
Cooling system
Coolant quantity
Radiator (including all routes)
Radiator cap valve opening pressure
Spark plug(s)
Manufacturer/model
Spark plug gap
Cylinder head
Warpage limit
Cylinder
Bore
Wear limit
Piston
Piston-to-cylinder clearance
Diameter
Measuring point (from piston skirt bottom)
Piston pin bore inside diameter limit
Piston pin outside diameter limit
Piston-pin-to-piston-pin-bore clearance
Piston ring
Top ring
End gap limit
Ring side clearance
Side clearance limit
ENGINE SPECIFICATIONS
2-stroke
Liquid cooled
Reed valve
125 cm³
Single cylinder
54.0  54.5 mm (2.13  2.15 in)
8.2–10.1 : 1
Kickstarter
Premium unleaded gasoline (E10 acceptable)
7.0 L (1.8 US gal, 1.5 Imp.gal)
YAMALUBE
Premix lubrication
YAMALUBE 2R
30
Motor oil SAE 10W-40 type SG or higher
0.76 L (0.80 US qt, 0.67 Imp.qt)
0.70 L (0.74 US qt, 0.62 Imp.qt)
0.90 L (0.95 US qt, 0.79 Imp.qt)
93.3–122.7 kPa (0.93–1.23 kgf/cm², 13.5–17.8
psi)
NGK/BR9EVX
0.6–0.7 mm (0.024–0.028 in)
0.03 mm (0.0012 in)
54.000–54.014 mm (2.1260–2.1265 in)
54.064 mm (2.1285 in)
0.040–0.045 mm (0.0016–0.0018 in)
53.957–53.972 mm (2.1243–2.1249 in)
17.5 mm (0.69 in)
15.040 mm (0.5921 in)
14.975 mm (0.5896 in)
0.008–0.023 mm (0.0003–0.0009 in)
1.20 mm (0.0472 in)
0.035–0.070 mm (0.0014–0.0028 in)
0.100 mm (0.0039 in)
2-2