Yamaha YZF-R1 2012, Service Manual, Page: 46 / 556

ENGINE SPECIFICATIONS
2-5
Valve spring
Inner spring
Free length (intake)
39.33 mm (1.55 in)
Limit 37.36 mm (1.47 in)
Free length (exhaust) 37.96 mm (1.49 in)
Limit 36.06 mm (1.42 in)
Installed length (intake) 34.50 mm (1.36 in)
Installed length (exhaust) 33.00 mm (1.30 in)
Spring rate K1 (intake) 41.57 N/mm (4.24 kgf/mm, 237.36 lbf/in)
Spring rate K2 (intake) 55.62 N/mm (5.67 kgf/mm, 317.59 lbf/in)
Spring rate K1 (exhaust) 40.10 N/mm (4.09 kgf/mm, 228.97 lbf/in)
Spring rate K2 (exhaust) 59.31 N/mm (6.05 kgf/mm, 338.66 lbf/in)
Installed compression spring force (intake) 187.00–215.00 N (19.07–21.92 kgf, 42.04–
48.33 lbf)
Installed compression spring force (exhaust) 185.00–213.00 N (18.86–21.72 kgf, 41.59–
47.88 lbf)
Spring tilt limit (intake) 2.5
°
/1.7 mm (0.067 in)
Spring tilt limit (exhaust) 2.5
°
/1.7 mm (0.067 in)
Winding direction (intake) Clockwise
Winding direction (exhaust) Clockwise
Cylinder
Bore 78.000–78.010 mm (3.0709–3.0713 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 0.150 mm (0.0059 in)
Piston diameter 77.975–77.990 mm (3.0699–3.0705 in)
Height H 12.0 mm (0.47 in)
Offset 0.00 mm (0.0000 in)
Piston pin bore inside diameter 17.002–17.013 mm (0.6694–0.6698 in)
Limit 17.043 mm (0.6710 in)
Piston pin outside diameter 16.991–17.000 mm (0.6689–0.6693 in)
Limit 16.971 mm (0.6682 in)
Piston-pin-to-piston-pin-bore clearance 0.002–0.022 mm (0.0001–0.0009 in)
Limit 0.072 mm (0.0028 in)
Piston ring
Top ring
Ring type Barrel
Dimensions (B
×
T) 0.90
×
2.75 mm (0.04
×
0.11 in)