1. Measure: valve spring free length (a)
Out of specification → Replace the valve spring.
![](https://motoinstruction.ru/img/yamaha/16/122303.jpg)
Valve spring free length (intake and exhaust):
- 44.6 mm
- Limit: 43.5 mm
2. Measure: compressed spring force (a)
Out of specification → Replace the valve spring.
![](https://motoinstruction.ru/img/yamaha/16/122304.jpg)
(b) Installed length
- Compressed spring force: Intake and exhaust spring 160.7 N (16.4 kg) at 40 mm
3. Measure: valve spring tilt (c)
Out of specification → Replace the valve spring.
![](https://motoinstruction.ru/img/yamaha/16/122305.jpg)
- Spring tilt limit: Intake and exhaust valve spring 2.5°/1.9 mm