Checking The Camshaft; Checking The Rocker Arms And Rocker Arm Shafts - Yamaha YZF-R125 Service Manual

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EAS23840

CHECKING THE CAMSHAFT

1. Check:
• Camshaft lobes
Blue discoloration/pitting/scratches → Re-
place the camshaft.
2. Measure:
• Camshaft lobe dimensions "a" and "b"
Out of specification → Replace the camshaft.
Camshaft lobe dimensions
Intake A
30.225–30.325 mm (1.1900–
1.1939 in)
Limit
30.125 mm (1.1860 in)
Intake B
25.127–25.227 mm (0.9893–
0.9932 in)
Limit
25.027 mm (0.9853 in)
Exhaust A
30.232–30.332 mm (1.1902–
1.1942 in)
Limit
30.132 mm (1.1863 in)
Exhaust B
25.065–25.165 mm (0.9868–
0.9907 in)
Limit
24.965 mm (0.9829 in)
3. Check:
• Camshaft oil passage
Obstruction → Blow out with compressed air.
EAS23880
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/pit-
ting/scratches → Replace or check the lubri-
cation system.
3. Measure:
• Rocker arm inside diameter "a"
Out of specification → Replace.
Rocker arm inside diameter
9.985–10.000 mm (0.3931–
0.3937 in)
Limit
10.015 mm (0.3943 in)
4. Measure:
• Rocker arm shaft outside diameter "a"
Out of specification → Replace.
Rocker arm shaft outside diame-
ter
9.966–9.976 mm (0.3924–0.3928
in)
Limit
9.941 mm (0.3914 in)
5-15
CAMSHAFT