Yamaha YZF-R25 Service Manual page 37

Limit
Valve guide inside diameter (exhaust)
Limit
Valve-stem-to-valve-guide clearance (intake)
Limit
Valve-stem-to-valve-guide clearance (exhaust)
Limit
Valve stem runout
Valve spring
Free length (intake)
Limit
Free length (exhaust)
Limit
Installed length (intake)
Installed length (exhaust)
Spring rate K1 (intake)
Spring rate K2 (intake)
Spring rate K1 (exhaust)
Spring rate K2 (exhaust)
Installed compression spring force (intake)
Installed compression spring force (exhaust)
Spring tilt (intake)
Spring tilt (exhaust)
Winding direction (intake)
Winding direction (exhaust)
Cylinder
Bore
Taper limit
Out of round limit
Piston
Piston-to-cylinder clearance
Diameter
Measuring point (from piston skirt bottom)
Offset
Piston pin bore inside diameter
Limit
Piston pin outside diameter
Limit
Piston-pin-to-piston-pin-bore clearance
Limit
Piston ring
Top ring
Ring type
End gap (installed)
Limit
Ring side clearance
Limit
ENGINE SPECIFICATIONS
4.550 mm (0.1791 in)
4.500–4.512 mm (0.1772–0.1776 in)
4.550 mm (0.1791 in)
0.010–0.037 mm (0.0004–0.0015 in)
0.080 mm (0.0032 in)
0.025–0.052 mm (0.0010–0.0020 in)
0.100 mm (0.0039 in)
0.010 mm (0.0004 in)
37.58 mm (1.48 in)
35.70 mm (1.41 in)
37.58 mm (1.48 in)
35.70 mm (1.41 in)
30.90 mm (1.22 in)
30.90 mm (1.22 in)
25.68 N/mm (2.62 kgf/mm, 146.63 lbf/in)
40.50 N/mm (4.13 kgf/mm, 231.26 lbf/in)
25.68 N/mm (2.62 kgf/mm, 146.63 lbf/in)
40.50 N/mm (4.13 kgf/mm, 231.26 lbf/in)
159.60–183.60 N (16.27–18.72 kgf, 35.88–
41.27 lbf)
159.60–183.60 N (16.27–18.72 kgf, 35.88–
41.27 lbf)
1.6 mm (0.06 in)
1.6 mm (0.06 in)
Clockwise
Clockwise
60.000–60.010 mm (2.3622–2.3626 in)
0.050 mm (0.0020 in)
0.050 mm (0.0020 in)
0.015–0.048 mm (0.0006–0.0019 in)
59.962–59.585 mm (2.3607–2.3459 in)
7.0 mm (0.28 in)
**
15.002–15.013 mm (0.5906–0.5911 in)
15.043 mm (0.5922 in)
14.995–15.000 mm (0.5904–0.5906 in)
14.975 mm (0.5896 in)
0.009–0.025 mm (0.0004–0.0010 in)
0.075 mm (0.0030 in)
Barrel
0.10–0.25 mm (0.0039–0.0098 in)
0.40 mm (0.0157 in)
0.030–0.065 mm (0.0012–0.0026 in)
0.100 mm (0.0039 in)
2-4