Yamaha YZF-R1 2020 Service Manual page 321

Valve-stem-to-valve-guide clear-
ance (intake)
0.010–0.037 mm (0.0004–0.0015
in)
Limit
0.080 mm (0.0032 in)
Valve-stem-to-valve-guide clear-
ance (exhaust)
0.025–0.052 mm (0.0010–0.0020
in)
Limit
0.100 mm (0.0039 in)
G088960
G088961
2. Replace:
• Valve guide
TIP
To ease valve guide removal and installation,
and to maintain the correct fit, heat the cylinder
head to 100 °C (212 °F) in an oven.
a. Remove the valve guide with the valve
guide remover "1".
G088962
VALVES AND VALVE SPRINGS
b. Install the new valve guide with the valve
guide installer "2" and valve guide remov-
er "1".
Valve guide position (intake)
12.0–12.4 mm (0.47–0.49 in)
Valve guide position (exhaust)
17.5–17.9 mm (0.69–0.70 in)
G088963
a. Valve guide position
c. After installing the valve guide, bore the
valve guide with the valve guide reamer
"3" to obtain the proper valve-stem-to-
valve-guide clearance.
G088964
TIP
After replacing the valve guide, reface the valve
seat.
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