Checking The Rocker Arms And Rocker Arm Shafts; Checking The Timing Chain And Camshaft Sprocket; Checking The Timing Chain Guides - Yamaha YZF-R1 Series Service Manual

Camshaft journal diameter
25.459–25.472 mm (1.0023–
1.0028 in)
G088949
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 → Replace.
2. Check:
• Rocker arm shaft
Blue discoloration/excessive wear/pitting/
scratches → Replace or check the lubrication
system.
3. Measure:
• Rocker arm inside diameter "a"
Out of specification → Replace.
Rocker arm inside diameter
7.987–8.002 mm (0.3144–0.3150
in)
Limit
8.017 mm (0.3156 in)
a
4. Measure:
• Rocker arm shaft outside diameter "a"
Out of specification → Replace.
Rocker arm shaft outside diame-
ter
7.967–7.979 mm (0.3137–0.3141
in)
Limit
7.936 mm (0.3124 in)
a
G088952
EAS30258
CHECKING THE TIMING CHAIN AND
CAMSHAFT SPROCKET
1. Check:
• Timing chain
Damage/stiffness → Replace the timing
chain and camshaft and camshaft sprocket
as a set.
2. Check:
• Camshaft sprocket
More than 1/4 tooth wear "a" → Replace the
camshaft sprockets and the timing chain as a
set.
a
b
G088950
a. 1/4 tooth
b. Correct
1. Timing chain
2. Camshaft sprocket
EAS30265

CHECKING THE TIMING CHAIN GUIDES

The following procedure applies to all of the
camshaft sprockets and timing chain guides.
1. Check:
• Timing chain guide (exhaust side)
• Timing chain guide (intake side)
5-26
CAMSHAFTS
1
2