Yamaha R1 Series 2015, Service Manual

Page: 357 / 704

CAMSHAFTS
5-16
EAS30259
CHECKING THE ROCKER ARMS AND
ROCKER ARM SHAFTS
The following procedure applies to all of the
rocker arms and rocker arm shafts.
1. Check:
•
Rocker arm
Damage/wear
o
Replace.
2. Check:
• Rocker arm shaft
Blue
discoloration/excessive wear/pit-
ting/scratches
o
Replace or check the lubri-
cation system.
3. Measure:
•
Rocker arm inside diameter “a”
Out of specification
o
Replace.
4. Measure:
•
Rocker arm shaft outside diameter “a”
Out of specification
o
Replace.
5. Calculate:
•
Rocker-arm-to-rocker-arm-shaft clearance
TIP
Calculate the clearance by subtracting the rock-
er arm shaft outside diameter from the rocker
arm inside diameter.
Out of specification
o
Replace.
EAS30258
CHECKING THE TIMING CHAIN AND
CAMSHAFT SPROCKET
1. Check:
• Timing chain
Damage/stiffness
o
Replace the timing
chain and camshaft and camshaft sprocket
as a set.
Camshaft journal diameter
25.459–25.472 mm (1.0023–
1.0028 in)
Rocker arm inside diameter
7.987–8.002 mm (0.3144–0.3150
in)
Limit
8.017 mm (0.3156 in)
Rocker arm shaft outside diame-
ter
7.967–7.979 mm (0.3137–0.3141
in)
Limit
7.936 mm (0.3124 in)
Rocker-arm-to-rocker-arm-shaft
clearance
0.008–0.035 mm (0.0003–0.0014
in)
Limit
0.080 mm (0.0032 in)
a
a