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Rally 200 CDI conversion
When your ignition unit goes belly up
| The
Rally 200 is a mean Vespa, but its weak spot is the FAMESA electronic
ignition. When it first appeared in 72 it represented a major step
forward because it replaced the old fashioned points ignition system
that failed to work properly quite often. "While initially
dependable, a problem with the FAMESA system occurred when the flywheel
side bearing would begin to wear out and permit some movement in
the crankshaft. It would cause the pickup sensor on the crank to
rub on the pickup, quickly burning the pickup coil and the high-tension
lead of the stator plate."- in "How to restore and maintain
your Vespa motorscooter", from uncles Bob. Also, the spark
plug cable has an annoying tendency to break where it exits the
housing, making the part unserviceable. The original part is not
only expensive, but hard to find. |
) Now
here's a typical original ignition unit. Broken down, burned up, busted,
pretty much screwed. The thick cable that exits from the left is the
spark plug cable. On the right you find three connections that are,
from left to right, red - green - blue. |
) First
you need to obtain an ignition unit from a PX, PK, Cosa, T5 or FL2.
The part isn't cheap if you buy it, but it should be quite easy to
get a second hand one, they very seldom break down (May 2003: have
in my possession a couple of PX CDIs that give out a weak spark; they
seem to work fine but the scooter stalls at the lights and is very
hard to start; not so reliable after all). The standard connections
are, from left to right, white - red- green - green, as it is inscribed
on the housing and as the sticker indicates. However, you should ignore
these indications.Two sets of wires exit the Rally 200 engine, one towards the electric connections box on top of the engine, and another towards the ignition unit. This last set of wires has 4 wires, black - green - red - blue. These wires are connected to the new ignition unit as shown on the photo. The fourth connector (on the right) is not used, as well as the blue wire. |
) The
new ignition unit can be attached by the lower pin that was used to
attach the old ignition unit, as the photo shows. The black wire (from
the CDI) is the ground wire and should be connected to the frame (
I don't think that's absolutely necessary, however). |
|
WARNING:
This conversion does not work with all Rally 200's! With
some, it works perfectly with excellent results. With others, the
engine will misfire and won't "rev up" if the lights are
on. |
Questions? Ask Mesquita