Yamaha 2003 YFZ450S, Service Manual

Page: 29 / 375

2 - 6
SPEC
ENGINE SPECIFICATIONS
Valve spring
Free length IN 37.03 mm (1.46 in) 35.17 mm
(1.38 in)
EX 37.68 mm (1.48 in) 35.79 mm
(1.41 in)
Set length (valve closed) IN 27.87 mm (1.10 in) ----
EX 27.38 mm (1.08 in) ----
Compressed pressure
(installed)
IN 111.3 ~ 127.9 N
(11.35 ~ 13.04 kg, 25.02 ~ 28.75 lb) ----
EX 127.4 ~ 146.4 N
(12.99 ~ 14.93 kg, 28.64 ~ 32.91 lb) ----
Tilt limit IN ---- 2.5°/1.61 mm
(2.5°/0.063 in)
EX ---- 2.5°/1.65 mm
(2.5°/0.065 in)
Direction of winding
(top view)
IN Clockwise ----
EX Clockwise ----
Piston
Piston to cylinder clearance 0.040 ~ 0.065 mm (0.0016 ~ 0.0026 in) 0.10 mm
(0.004 in)
Piston size “D” 94.945 ~ 94.960 mm (3.7380 ~ 3.7386 in) ----
Measuring point “H” 10 mm (0.39 in) ----
Piston off set 1.0 mm (0.0394 in) ----
Offset direction Intake side ----
Piston pin bore inside diameter 20.004 ~ 20.015 mm (0.7876 ~ 0.7880 in) 20.045 mm
(0.789 in)
Piston pin outside diameter 19.991 ~ 20.000 mm (0.7870 ~ 0.7874 in) 19.971 mm
(0.786 in)
Piston-pin-to-piston-pin-bore clear-
ance 0.004 ~ 0.024 mm (0.0002 ~ 0.0009 in) 0.074 mm
(0.0029 in)
Item Standard Limit
H
D