- Camshaft lobes
Blue discoloration/pitting/scratches → Replace the camshaft.
2. Measure:
- Camshaft lobe dimensions «a» and «b». Out of specification → Replace the camshaft.
Camshaft lobe dimension limit:
- Intake camshaft «a»: 32.50–32.60 mm (1.280–1.284 in)
- Limit: 32.40 mm (1.276 in)
- Intake camshaft «b»: 24.95-25.05 mm (0.982-0.986 in)
- Limit: 24.85 mm (0.978 in)
- Exhaust camshaft «a»: 30.70-30.80 mm (1.209-1.213 in)
- Limit: 30.60 mm (1.205 in)
- Exhaust camshaft «b»: 22.95–23.05 mm (0.904–0.908 in)
- Limit 22.85 mm (0.900 in)
![]() | ![]() |
3. Measure:
- Camshaft runout.
Out of specification → Replace.
![](https://motoinstruction.ru/img/yamaha/3/111799.jpg)
4. Measure:
- Camshaft-journal-to-camshaft-cap clearance
Out of specification → Measure the camshaft journal diameter.
Camshaft-journal-to-camshaft-cap clearance: 0.028-0.062 mm (0.0011-0.0024 in)
a. Install the camshaft into the cylinder head (without the dowel pins and camshaft caps).
b. Position strip of Plastigauge® «1» onto the camshaft journal as shown.
c. Install the dowel pins and camshaft caps.
Notes:
- 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 clearance with the Plastigauge®.
Camshaft cap bolt: 10 Nm (1.0 m·kg, 7.2 ft·lb)
d. Remove the camshaft caps and then measure the width of the Plastigauge® «2».
![](https://motoinstruction.ru/img/yamaha/3/111800.jpg)
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.
Camshaft journal diameter: 22.459-22.472 mm (0.8842-0.8847 in)
![](https://motoinstruction.ru/img/yamaha/3/111801.jpg)