Yamaha RST90GTZ, Service Manual

Page: 438 / 504

SPEC
9-5
Item Description
Valves, valve seats, valve guides:
Valve clearance (cold)
Intake 0.15 ~ 0.22 mm (0.0059 ~ 0.0087 in)
Exhaust 0.21 ~ 0.25 mm (0.0083 ~ 0.0098 in)
Valve dimensions
Valve head diameter A
Intake 30.90 ~ 31.10 mm (1.2165 ~ 1.2244 in)
Exhaust 25.90 ~ 26.10 mm (1.0197 ~ 1.0276 in)
Valve face width B
Intake 1.90 ~ 2.62 mm (0.0748 ~ 0.1031 in)
Exhaust 1.90 ~ 2.62 mm (0.0748 ~ 0.1031 in)
Valve seat width C
Intake 0.90 ~ 1.10 mm (0.0354 ~ 0.0433 in)
Exhaust 0.90 ~ 1.10 mm (0.0354 ~ 0.0433 in)
Valve margin thickness D
Intake 0.80 ~ 1.20 mm (0.0315 ~ 0.0472 in)
Exhaust 0.50 ~ 0.90 mm (0.0197 ~ 0.0354 in)
Valve stem diameter
Intake 4.475 ~ 4.490 mm (0.1762 ~ 0.1768 in)
<Limit> 4.445 mm (0.1750 in)
Exhaust 4.460 ~ 4.475 mm (0.1756 ~ 0.1762 in)
<Limit> 4.430 mm (0.1744 in)
Valve guide inside diameter
Intake 4.500 ~ 4.512 mm (0.1772 ~ 0.1776 in)
<Limit> 4.550 mm (0.1791 in)
Exhaust 4.500 ~ 4.512 mm (0.1772 ~ 0.1776 in)
<Limit> 4.550 mm (0.1791 in)
Valve-stem-to-valve-guide clearance
Intake 0.010 ~ 0.037 mm (0.0004 ~ 0.0015 in)
<Limit> 0.080 mm (0.0031 in)
Exhaust 0.025 ~ 0.052 mm (0.0010 ~ 0.0020 in)
<Limit> 0.100 mm (0.0039 in)
Valve stem runout limit 0.010 mm (0.0004 in)
Valve seat width
Intake 0.90 ~ 1.10 mm (0.0354 ~ 0.0433 in)
<Limit> 1.6 mm (0.0630 in)
Exhaust 0.90 ~ 1.10 mm (0.0354 ~ 0.0433 in)
<Limit> 1.6 mm (0.0630 in)
MAINTENANCE SPECIFICATIONS