Checking The Timing Chain And Sprocket - Yamaha YZF-R1(B) 2012 Service Manual

4. Measure:
• Camshaft-journal-to-camshaft-cap clear-
ance
Out of specification → Measure the cam-
shaft journal diameter.
Camshaft-journal-to-camshaft-
cap clearance
0.028–0.062
0.0024 in)
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a. Install the camshaft into the cylinder head
(without the camshaft caps).
b. Position strip of Plastigauge® "1" onto the
camshaft journal as shown.
c. Install the camshaft caps.
TIP
• Tighten the camshaft cap bolts in stages and
in a crisscross pattern, working from the
inner caps out.
• Do not turn the camshaft when measuring
the camshaft journal-to-camshaft cap clear-
ance with the Plastigauge®.
Camshaft cap bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
d. Remove the camshaft caps and then mea-
sure the width of the Plastigauge® "2".
mm (0.0011–
5-18
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5. Measure:
• Camshaft journal diameter "a"
Out of specification → Replace the cam-
shaft.
Within specification → Replace the cylin-
der head and the camshaft caps as a set.
Camshaft journal diameter
25.459–25.472 mm (1.0023–
1.0028 in)
EAS23870
CHECKING THE TIMING CHAIN AND
SPROCKET
1. Check:
• Timing chain
Damage/stiffness → Replace the timing
chain, camshaft sprockets and crankshaft
sprocket as a set.
2. Check:
• Camshaft sprocket
• Crankshaft sprocket
More than 1/4 tooth wear "a" → Replace
the camshaft sprockets, crankshaft
sprocket and timing chain as a set.
CAMSHAFTS