Yamaha 2008 YZF-R6X, Service Manual

Page: 36 / 434

ENGINE SPECIFICATIONS
2-5
Valve stem runout 0.040 mm (0.0016 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) 1.10–1.30 mm (0.0433–0.0512 in)
Limit 1.8 mm (0.07 in)
Valve spring
Free length (intake) 37.47 mm (1.48 in)
Limit 35.60 mm (1.40 in)
Free length (exhaust) 37.67 mm (1.48 in)
Limit 35.79 mm (1.42 in)
Installed length (intake) 32.80 mm (1.29 in)
Installed length (exhaust) 32.80 mm (1.29 in)
Spring rate K1 (intake) 38.11 N/mm (217.61 lb/in) (3.89 kgf/mm)
Spring rate K2 (intake) 52.40 N/mm (299.20 lb/in) (5.34 kgf/mm)
Spring rate K1 (exhaust) 36.36 N/mm (207.62 lb/in) (3.71 kgf/mm)
Spring rate K2 (exhaust) 53.40 N/mm (304.91 lb/in) (5.45 kgf/mm)
Installed compression spring force (intake) 166.00–190.00 N (37.32–42.71 lbf) (16.93–
19.37 kgf)
Installed compression spring force (exhaust) 165.00–189.00 N (37.09–42.49 lbf) (16.83–
19.27 kgf)
Spring tilt (intake) 2.5
°
/1.6 mm
Spring tilt (exhaust) 2.5
°
/1.6 mm
Winding direction (intake) Clockwise
Winding direction (exhaust) Clockwise
Cylinder
Bore 67.000–67.010 mm (2.6378–2.6382 in)
Taper limit 0.050 mm (0.0020 in)
Out of round limit 0.050 mm (0.0020 in)
Piston
Piston-to-cylinder clearance 0.010–0.035 mm (0.0004–0.0014 in)
Limit 0.05 mm (0.0022 in)
Diameter D 66.975–66.990 mm (2.6368–2.6374 in)
Height H 10.0 mm (0.39 in)
H
D