Yamaha XMAX 125, Service Manual

Page: 36 / 498

ENGINE SPECIFICATIONS (YP125R)
2-5
Limit 0.5 mm (0.02 in)
Valve stem diameter (intake) 4.475–4.490 mm (0.1762–0.1768 in)
Limit 4.445 mm (0.1750 in)
Valve stem diameter (exhaust) 4.460–4.475 mm (0.1756–0.1762 in)
Limit 4.430 mm (0.1744 in)
Valve guide inside diameter (intake) 4.500–4.512 mm (0.1772–0.1776 in)
Limit 4.550 mm (0.1791 in)
Valve guide inside diameter (exhaust) 4.500–4.512 mm (0.1772–0.1776 in)
Limit 4.550 mm (0.1791 in)
Valve-stem-to-valve-guide clearance (intake) 0.010–0.037 mm (0.0004–0.0015 in)
Limit 0.080 mm (0.0031 in)
Valve-stem-to-valve-guide clearance (exhaust) 0.025–0.052 mm (0.0010–0.0020 in)
Limit 0.100 mm (0.0039 in)
Valve stem runout 0.010 mm (0.0004 in)
Cylinder head valve seat width (intake) 0.90–1.10 mm (0.0354–0.0433 in)
Limit 1.6 mm (0.06 in)
Cylinder head valve seat width (exhaust) 0.90–1.10 mm (0.0354–0.0433 in)
Limit 1.6 mm (0.06 in)
Valve spring
Free length (intake) 41.71 mm (1.64 in)
Limit 39.62 mm (1.56 in)
Free length (exhaust) 41.71 mm (1.64 in)
Limit 39.62 mm (1.56 in)
Installed length (intake) 35.30 mm (1.39 in)
Installed length (exhaust) 35.30 mm (1.39 in)
Spring rate K1 (intake) 23.54 N/mm (2.40 kgf/mm, 134.41 lb/in)
Spring rate K2 (intake) 36.58 N/mm (3.73 kgf/mm, 208.87 lb/in)
Spring rate K1 (exhaust) 23.54 N/mm (2.40 kgf/mm, 134.41 lb/in)
Spring rate K2 (exhaust) 36.58 N/mm (3.73 kgf/mm, 208.87 lb/in)
Installed compression spring force (intake) 140–162 N (14.28–16.52 kgf, 31.47–36.42 lbf)
Installed compression spring force (exhaust) 140–162 N (14.28–16.52 kgf, 31.47–36.42 lbf)
Spring tilt (intake) 2.5°/1.8 mm
Spring tilt (exhaust) 2.5°/1.8 mm
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