Yamaha Wolverine YX70EPNG, Service Manual

Page: 37 / 503

ENGINE SPECIFICATIONS
2-4
Valve-stem-to-valve-guide clearance (intake)
limit 0.080 mm (0.0031 in)
Valve-stem-to-valve-guide clearance
(exhaust) limit 0.100 mm (0.0039 in)
Valve stem runout 0.040 mm (0.0016 in)
Valve spring
Installed length (intake) 30.95 mm (1.22 in)
Installed length (exhaust) 32.20 mm (1.27 in)
Installed compression spring force (intake) 134.00–154.00 N (13.66–15.70 kgf, 30.12–
34.62 lbf)
Installed compression spring force (exhaust) 107.00–123.00 N (10.91–12.54 kgf, 24.05–
27.65 lbf)
Spring tilt (intake) 1.7 mm (0.07 in)
Spring tilt (exhaust) 1.7 mm (0.07 in)
Winding direction (intake) Clockwise
Winding direction (exhaust) Clockwise
Cylinder
Bore 103.000–103.020 mm (4.0551–4.0559 in)
Wear limit 103.080 mm (4.0583 in)
Taper limit 0.050 mm (0.0020 in)
Out of round limit 0.050 mm (0.0020 in)
Piston
Piston-to-cylinder clearance 0.040–0.075 mm (0.0016–0.0030 in)
Diameter 102.960–102.975 mm (4.0535–4.0541 in)
Measuring point (from piston skirt bottom) 11.0 mm (0.43 in)
Piston pin bore inside diameter limit 23.035 mm (0.9069 in)
Piston pin outside diameter limit 22.974 mm (0.9045 in)
Piston ring
Top ring
Ring type Barrel
End gap (installed) limit 0.50 mm (0.0197 in)
Ring side clearance limit 0.12 mm (0.0047 in)
2nd ring
Ring type
End gap (installed) limit 0.70 mm (0.0276 in)
Ring side clearance limit 0.12 mm (0.0047 in)
Oil ring
End gap (installed) limit 1.0 mm (0.039 in)
Crankshaft
Crank assembly width 65.68–65.76 mm (2.586–2.589 in)
Runout limit 0.030 mm (0.0012 in)
Big end side clearance 0.090–0.500 mm (0.0035–0.0197 in)
Clutch
Clutch type Wet, centrifugal automatic
Clutch shoe thickness limit 1.0 mm (0.04 in)
Clutch housing inside diameter 150.0 mm (5.91 in)
Clutch-in revolution 1950–2050 r/min