PIAGGIO MSS X9 EVOLUTION 250 - Inspecting the Automatic Choke Device

- Check that the diaphragm is not worn or has
hardened.
If it does, replace it.
- Refit the tapered pin on the vacuum valve.
- Make sure the spring is in the correct position on
the plunger and inserted in its housing.
- Assemble the coupling by rotating it 1/8 of a turn.
- Reassemble the vacuum gas valve on the car-
burettor body being careful that the tapered pin is
inserted into the sprayer.
- Time the vacuum valve rotation inserting the di-
aphragm tab in its place.
When the diaphragm is correctly assembled to the
valve, the main vacuum supply hole is positioned
axially with the diffuser, on the throttle valve side.
- Refit the spring on the valve.
- Refit the vacuum chamber cover matching the
reference mark with the orientation of the dia-
phragm.
- Tighten the screws to the prescribed torque.
- Check the cut-off valve correct functioning. -
Check that the diaphragm is not worn or has hard-
ened. Check the free length of the spring.
Characteristic
Walbro: Standard length of cut-off spring
24 mm
- Reassemble the diaphragm and the metal pin placed on the valve.
- Reassemble the spring and the cover. The vacuum intake should be facing upwards.
Inspecting the automatic choke device
Engine MSS X9 Evolution 250
ENG - 166