Removing the oil sump
- Remove the oil filler plug, the transmission cover,
the complete driving pulley assembly with belt and
the sprocket wheel, as described in the "Trans-
mission" chapter.
- Drain the oil as described above.
- Remove the 7 screws, shown in the diagram, and
the 2 rear brake fluid pipe fixing brackets.
- Remove the screw, the by-pass piston, the gas-
ket and the centring dowels shown in the figure.
Inspecting the by-pass valve
- Check the unloaded spring length.
- Check that the small piston is not scored.
- Ensure that it slides freely on the crankcase and that it guarantees a good seal.
- If not, eliminate any impurities or replace defective parts.
Characteristic
By-pass check up: Standard length
54.2 mm
X9 Evolution 125 Engine
ENG - 149