Vespa Small Frame Engine Work

Flywheel Removal

Removing the flywheel allows you access to the stator for timing purposes, access to the flywheel side oil seal, and must be done before splitting the casings.

You will need:

  • A 17mm socket & driver
  • A flywheel puller tool and two wrenches to turn it
  • A flathead screwdriver
  • A flywheel holding tool (not absolutely required)

Put the bike on its stand and remove the right hand side engine panel by turning the latch at the top and hinging it out at the bottom.

There are 4 machine bolts (red arrows) and a screw (blue arrow) that need to be removed in order to remove the flywheel fan shroud. Once the bolts are removed, pull the shroud out from the bottom so the top can slide out from under the plastic cylinder shroud.

Pry out the plastic cover over the central flywheel nut with a screwdriver or just by hand. On this flywheel I was able to use a typical P series holding tool due to the slot with a rubber bung in it. You can always lock the flywheel by jamming a screwdriver between a fin and the casing but you run the risk of breaking the fin. The correct way to do it is with a flywheel holding tool. This will hold the flywheel while you remove the single 17mm nut with a socket & driver.

Be sure to save the nut and the thin shake proof washer behind it for reattaching the flywheel when you are done. If your flywheel nut doesn't look like this and has a small circlip inside the recess, try the older Vespa flywheel removal page.

The flywheel is mounted on a taper on the end of the crank and cannot just be removed once the nut is free. Fit the threaded flywheel puller into the flywheel center. Make sure the threaded section is screwed in as far as it will go as there will be stress on these threads and if they are stripped or damaged it will make future removals a pain.

Use one wrench to hold the flywheel puller body in place, and the other to tighten down the central bolt. As you turn these together there will be a pop and the flywheel will then be loose.

Carefully lift the flywheel off. You may feel some resistance but it is only caused by magnets within the flywheel body reacting with the coils. Once the flywheel is clear be sure to look on the crank taper for the locating woodruff key. Sometimes these remain stuck in the keyway, but other times they fall free and can be easily lost.