Yamaha YZ450FY 2009 Owner's Service Manual page 36

Item
Timing chain:
Timing chain type/No. of links
Timing chain adjustment method
Valve, valve seat, valve guide:
Valve clearance (cold)
IN
EX
Valve dimensions:
"A" head diameter (IN)
"A" head diameter (EX)
"B" face width (IN)
"B" face width (EX)
"C" seat width (IN)
"C" seat width (EX)
"D" margin thickness (IN)
"D" margin thickness (EX)
Stem outside diameter (IN)
Stem outside diameter (EX)
MAINTENANCE SPECIFICATIONS
Standard
98XRH2010-118M/118
Automatic
0.10–0.15 mm (0.0039–0.0059 in) ----
0.20–0.25 mm (0.0079–0.0098 in) ----
26.9–27.1 mm (1.0591–1.0669 in) ----
27.9–28.1 mm (1.0984–1.1063 in) ----
2.26 mm (0.089 in)
2.26 mm (0.089 in)
0.9–1.1 mm (0.0354–0.0433 in)
0.9–1.1 mm (0.0354–0.0433 in)
1 mm (0.0394 in)
1 mm (0.0394 in)
4.475–4.490 mm (0.1762–0.1768
in)
4.965–4.980 mm (0.1955–0.1961
in)
2-5
Limit
----
----
----
----
1.6 mm
(0.0630 in)
1.6 mm
(0.0630 in)
0.85 mm
(0.033 in)
0.85 mm
(0.033 in)
4.445 mm
(0.1750 in)
4.935 mm
(0.1943 in)