Inspecting The By-Pass Valve; Refitting The Oil Sump - VESPA GTS 250 I.E. Workshop Manual

Vespa GTS 250 I.E.

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 defec-
tive parts.
Characteristic
By-pass check up: Standard length
54.2 mm

Refitting the oil sump

- Refit the by-pass valve plunger in its housing.
- Insert the pressure-regulating spring.
- Fit a new sump seal.
- Refit the two centring dowels.
- Refit the sump, taking care to locate the spring in
the appropriate recess machined into the inside of
the sump.
- Refit the rear brake cable brackets and the
screws in the reverse order from which they were
removed.
- Tighten the screws to the prescribed torque.
- Refit the drive pulley assembly, the drive belt, the
sprocket wheel and the transmission cover, as de-
scribed in the "Transmissions" chapter.
- When testing the lubrication system, refer to
chapter "Crankcase and Crankshaft", regard-
ing lubrication of the crankshaft and connect-
ing rod
Locking torques (N*m)
Oil sump screws 10 ÷ 14
Engine
ENG - 65