And this form MartinM.
http://www.rotaxsales.be/download/280cctrialSWM1980.pdf
** When you change the gear oil its the allan key on the sump, do not touch the flat hex nut beside it which is the kickstart return spring.
Is it points ignition ? If so and you aren't using lights, you probably dont need a rectifier.
Trace the wire from the points, then connect it to the coil with a condensor mounted by the coil.
Akront rims usaually have the WM size stamped on the rim.
Got Talon rimlocks, no better at securing the tyre (in my experience) but should last longer than standard ones.