Checking The Camshafts - Yamaha MT-09 2021 Service Manual

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EAS30257

CHECKING THE CAMSHAFTS

1. Check:
• Camshaft lobes
Blue discoloration/pitting/scratches → Re-
place the camshaft.
2. Measure:
• Camshaft lobe dimensions "a"
Out of specification → Replace the camshaft.
Camshaft lobe dimensions
Lobe height limit (Intake)
35.590 mm (1.4012 in)
Lobe height limit (Exhaust)
35.620 mm (1.4024 in)
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3. Measure:
• Camshaft runout
Out of specification → Replace.
Camshaft runout limit
0.030 mm (0.0012 in)
4. Measure:
• Camshaft-journal-to-camshaft-cap clearance
Out of specification → Measure the camshaft
1
journal diameter.
a. Install the camshaft into the cylinder head
(without the camshaft caps).
b. Position strip of Plastigauge® "1" onto the
camshaft journal as shown.
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c. Install the dowel pins and camshaft caps.
Refer to "INSTALLING THE CAMSHAFTS"
on page 5-22.
TIP
Do not turn the camshaft when measuring the
camshaft journal-to-camshaft cap clearance
with the Plastigauge®.
d. Remove the camshaft caps, and then mea-
sure the width of the Plastigauge® "1".
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5. Measure:
• Camshaft journal diameter "a"
Out of specification → Replace the camshaft.
Within specification → Replace the cylinder
head and the camshaft caps as a set.
5-20
CAMSHAFTS
Camshaft-journal-to-camshaft-
cap clearance limit
0.080 mm (0.0032 in)
1
Camshaft journal diameter
24.459–24.472 mm (0.9630–
0.9635 in)
1