Vespa Oil Seals Maintenance: Flywheel Side

There are three main oil seals in a Vespa engine:

• Main bearing oil seal (at the crank): Keeps the gearbox oil from mixing with the oil/gas mixture.
• Flywheel side oil seal (at the crank): Keeps the oil/gas mix from the outside of the casing.
• Rear wheel oil seal: Seals the gearbox oil around the rear axle.

There are also some more minor seals around the kickstart quadrant, the clutch cover, and the rear wheel back plate.

The main seals should be replaced every time the engine is taken apart as they are cheap to buy but they are buried pretty deep in the engine. If you have the engine apart you might as well drop them in.

Flywheel side seal: The flywheel side seal on a typical P series motor is shown below on the left once the stator plate and crank have been removed. The seal is the black rubber like ring visible just in front of the bearing. It can be removed with a small screwdriver if care is taken not to damage the roller bearing beyond as shown on the right. This is also possible to do with the crank still in the machine but the clutch side seal is not.

Fitting a new flywheel side seal is as simple as pushing the seal into place firmly with equal pressure on all sides as shown below.