Re: year of motor
109B62B is the model number!
It is the number for a 1979 model but is is not included in the BRP parts catalog.
Is it a Belgium built model ? Are you in the UK?
If it is an electric start model then it almost certainly will have battery charging. Look for a rectifier. A round thing about 2.5-3 cm diameter on a triangular two bolt flange mounted on the side of the power head ( on the exhaust manifold cover to be precise) with 4 wires (a red, and 3 yellows) coming from it to a nearby terminal strip.
AFAIK it will not have a lighting coil. Either the battery charging stator coil and rectifier or not. But look for the terminal strip. If that's there with 3 yellow wires connected to it then the battery charging stator is fitted.