Vespa Large Frame Overview
Large Frame Overview
The large frame casing was retrofitted to be able to carry an electric start function similar to the small frame system. The difference is that the starter motor cannot stick out straight from the casing so it has a 90 degree gear and a recessed area of the flywheel casing t fit in between the motor and the rear shock. The only different parts that consititute the electric start system are the cases, the starter motor, and the flywheel. Everything else within the motor is the same as a non electric start motor.
All new casings come with a starter area
cast in to them, although if the motor was not electric start to begin
with the casting has not been machined around the starter hole, and the
hole hasn't been drilled - click for a larger image
The starter motor:
The electric start system works by using
an electric motor to extend a gear onto a toothed flywheel. Below are
shots of the motor and how the process of it turning extends a small
toothed gear (similar to the kickstart gear) which turns the flywheel.
The flywheel is very similar to a normal
flywheel except that it has a friction fitting ring gear all the way
around the perimeter. This gear engaes with the starter motor gear when
the bendix gear pops out of the starter motor.