Yamaha YFZ450S 2003 Service Manual page 28

Item
Valve, valve seat, valve guide
Valve clearance (cold)
Valve dimensions
A
Head Diameter
"A" head diameter
"B" face width
"C" seat width
"D" margin thickness
Stem outside diameter
Guide inside diameter
Stem-to-guide clearance IN
Valve stem runout
Valve seat width
ENGINE SPECIFICATIONS
IN 0.10 ~ 0.15 mm (0.0039 ~ 0.0059 in)
EX 0.20 ~ 0.25 mm (0.0079 ~ 0.0098 in)
B
Face Width
IN 26.9 ~ 27.1 mm (1.0591 ~ 1.0669 in)
EX 27.9 ~ 28.1 mm (1.0984 ~ 1.1063 in)
IN 2.26 mm (0.0890 in)
EX 2.26 mm (0.0890 in)
IN 0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)
EX 0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)
IN 1.0 mm (0.0394 in)
EX 1.0 mm (0.0394 in)
IN 4.475 ~ 4.490 mm (0.1762 ~ 0.1768 in)
EX 4.965 ~ 4.980 mm (0.1955 ~ 0.1961 in)
IN 4.500 ~ 4.512 mm (0.1772 ~ 0.1776 in)
EX 5.000 ~ 5.012 mm (0.1969 ~ 0.1973 in)
0.010 ~ 0.037 mm (0.0004 ~ 0.0015 in)
EX 0.020 ~ 0.047 mm (0.0008 ~ 0.0019 in)
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IN 0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)
EX 0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)
2 - 5
Standard
C
Seat Width
SPEC
Limit
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D
Margin Thickness
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1.6 mm
(0.06 in)
1.6 mm
(0.06 in)
0.85 mm
(0.033 in)
0.85 mm
(0.033 in)
4.445 mm
(0.175 in)
4.935 mm
(0.194 in)
4.550 mm
(0.179 in)
5.050 mm
(0.199 in)
0.080 mm
(0.003 in)
0.100 mm
(0.004 in)
0.01 mm
(0.0004 in)
1.6 mm
(0.06 in)
1.6 mm
(0.06 in)