Yamaha YZ125 2015, Owner'S Service Manual

Page: 27 / 166

2-3
MAINTENANCE SPECIFICATIONS
MAINTENANCE SPECIFICATIONS
ENGINE
Item Standard Limit
Cylinder head:
Combustion chamber volume 8.40–8.60 cm
3
(0.51–0.52 cu.in) ----
Warp limit ---- 0.03 mm
(0.0012 in)
Cylinder:
Bore size 54.000–54.014 mm (2.1260–2.1265 in) 54.100 mm
(2.1299 in)
Taper limit ---- 0.050 mm
(0.0020 in)
Out of round limit ---- 0.010 mm
(0.0004 in)
Piston:
Piston size/ 53.957–53.972 mm (2.1243–2.1249 in) ----
Measuring point "H" 17.5 mm (0.69 in) ----
Piston clearance 0.040–0.045 mm (0.0016–0.0018 in) 0.100 mm
(0.0039 in)
Piston offset 0.50 mm (0.0197 in)/EX-side ----
Piston pin:
Piston pin outside diameter 14.995–15.000 mm (0.5904–0.5906 in) 14.975 mm
(0.5896 in)
Piston ring:
Sectional sketch Plain ----
B=1.00 mm (0.04 in) ----
T=2.35 mm (0.09 in) ----
End gap (installed) 0.50–0.70 mm (0.0197–0.0276 in) 1.20 mm
(0.0472 in)
Side clearance (installed) 0.035–0.070 mm (0.0014–0.0028 in) 0.100 mm
(0.0039 in)