Yamaha YZ450FX 2021 Owner's Service Manual page 48

Valve dimensions
Valve seat contact width limit (intake)
Valve seat contact width limit (exhaust)
Valve stem diameter limit (intake)
Valve stem diameter limit (exhaust)
Valve guide inside diameter (intake)
Valve guide inside diameter (exhaust)
Valve-stem-to-valve-guide clearance limit
(intake)
Valve-stem-to-valve-guide clearance limit
(exhaust)
Valve stem runout
Valve spring
Free length limit (intake)
Free length limit (exhaust)
Cylinder
Bore
Wear limit
Piston
Piston-to-cylinder clearance
Diameter
Measuring point (from piston skirt bottom)
Piston pin bore inside diameter limit
Piston pin outside diameter limit
Piston-pin-to-piston-pin-bore clearance
Piston ring
Top ring
End gap limit
Ring side clearance
Side clearance limit
2nd ring
End gap limit
Ring side clearance
Side clearance limit
Crankshaft
Crank assembly width
Runout limit
Clutch
Clutch type
Clutch lever free play
Friction plate 1 thickness
Wear limit
Plate quantity
Friction plate 2 thickness
Wear limit
Plate quantity
Clutch plate thickness
Plate quantity
Warpage limit
Clutch spring free length
ENGINE SPECIFICATIONS
1.5 mm (0.06 in)
1.5 mm (0.06 in)
5.445 mm (0.2144 in)
5.435 mm (0.2140 in)
5.500–5.512 mm (0.2165–0.2170 in)
5.500–5.512 mm (0.2165–0.2170 in)
0.080 mm (0.0032 in)
0.100 mm (0.0039 in)
0.020 mm (0.0008 in)
36.65 mm (1.44 in)
35.55 mm (1.40 in)
97.000–97.010 mm (3.8189–3.8193 in)
97.060 mm (3.8213 in)
0.010–0.045 mm (0.0004–0.0018 in)
96.955–96.970 mm (3.8171–3.8177 in)
9.0 mm (0.35 in)
18.045 mm (0.7104 in)
17.981 mm (0.7079 in)
0.004–0.024 mm (0.0002–0.0009 in)
0.55 mm (0.0217 in)
0.015–0.065 mm (0.0006–0.0026 in)
0.120 mm (0.0047 in)
0.85 mm (0.0335 in)
0.020–0.060 mm (0.0008–0.0024 in)
0.100 mm (0.0039 in)
61.93–62.00 mm (2.438–2.441 in)
0.030 mm (0.0012 in)
Wet, multiple-disc
7.0–12.0 mm (0.28–0.47 in)
2.92–3.08 mm (0.115–0.121 in)
2.82 mm (0.111 in)
6 pcs
2.92–3.08 mm (0.115–0.121 in)
2.82 mm (0.111 in)
2 pcs
1.50–1.70 mm (0.059–0.067 in)
7 pcs
0.10 mm (0.004 in)
48.00 mm (1.89 in)
2-3