Vespa Small Frame Engine Work


Installing a crank

Installing a crank is pretty easy Here's what you will need:

  • 17mm socket & driver
  • A flathead screwdriver
  • Two small blocks of wood or some soft metal like a dime or penny.
  • A rubber faced mallet or a hammer and block of wood.
  • Some pliers

Once you have replaced the crank side oil seal, amke sure you grease the lip before putting the crank end through the bearing. The crank will only go in in one direction. The tapered shaft should be facing out towards you and the straight shaft goes through the bearing.

The crank should fit through the bearing by hand force alone, and stick out the other side as shown above.

The clutch basket has a special cut out are that should be rotated so that it aligns with the shaft of the crank. This is the only position that the crank gear will be able to mesh with the clutch gear. Place a woodruff keu in the slot on the crank end and slide the gear down over it. I can't notice a difference on either side of the crank gear so it looks like it can go on either way.

This is followed by a washer with a special peg which also slots in to the crank end.

Followed by a 17mm nut. Tighten the nut by either locking the motor with a con rod tool, or jamming a rag in the gear teeth. When it is tight, bend one side of the washer up over the nut to hold it in place

When it is tight, bend one side of the washer up over the nut to hold it in place.