Yamaha 2011 WR250FA, Owner'S Service Manual

Page: 47 / 316

2-7
MAINTENANCE SPECIFICATIONS
Piston:
Piston to cylinder clearance 0.030–0.055 mm (0.0012–0.0022
in) 0.1 mm
(0.004 in)
Piston size "D" 76.955–76.970 mm (3.0297–
3.0303 in) ----
Measuring point "H" 8 mm (0.31 in) ----
Piston off-set 0.5 mm (0.020 in)/IN-side ----
Piston pin bore inside diameter 16.002–16.013 mm (0.6300–
0.6304 in) 16.043 mm
(0.6316 in)
Piston pin outside diameter 15.991–16.000 mm (0.6296–
0.6299 in) 15.971 mm
(0.6288 in)
Piston rings:
Top ring:
Type Barrel ----
Dimensions (B × T) 0.90 × 2.75 mm (0.04 × 0.11 in) ----
End gap (installed) 0.15–0.25 mm (0.006–0.010 in) 0.50 mm
(0.020 in)
Side clearance (installed) 0.030–0.065 mm (0.0012–0.0026
in) 0.12 mm
(0.005 in)
2nd ring:
Type Taper ----
Dimensions (B × T) 0.80 × 2.75 mm (0.03 × 0.11 in) ----
End gap (installed) 0.30–0.45 mm (0.012–0.018 in) 0.80 mm
(0.031 in)
Side clearance 0.020–0.055 mm (0.0008–0.0022
in) 0.12 mm
(0.005 in)
Oil ring:
Dimensions (B × T) 1.50 × 2.25 mm (0.06 × 0.09 in) ----
End gap (installed) 0.10–0.40 mm (0.004–0.016 in) ----
Item Standard Limit