Out of specification → Replace the piston and piston rings as a set.
Note: Before measuring the piston ring side clearance, eliminate any carbon deposits from the piston ring grooves and piston rings.
Piston ring side clearance:
- Top ring:
- 0.04-0.08 mm
- Limit: 0.1 mm
- 2nd ring:
- 0.03-0.07 mm
- Limit: 0.1 mm
![](https://motoinstruction.ru/img/yamaha/16/122315.jpg)
2. Install: piston ring (into the cylinder)
Note: Using the piston crown pash the ring into the cylinder so that the ring will be at a right angle to the cylinder bore.
![](https://motoinstruction.ru/img/yamaha/16/122316.jpg)
(a) 40 mm from the top of the cylinder
3. Measure: piston ring end gap
Out of specification → Replace the piston ring.
Note: The oil ring expander spacer's end gap cannot be measured. If the oil ring rail's gap is excessive, replace all three piston rings.
Piston ring end gap:
- Top ring:
- 0.3-0.5 mm
- Limit: 0.8 mm
- 2nd ring:
- 0.3-0.45 mm
- Limit: 0.8 mm
- Oil ring:
- 0.2-0.7 mm