On another subject, if you look at the pictures in Rong's thread (a link to which has been posted twice previously in this thread), you will see that the HD8 is not supposed to have a battery or battery box: that is one of the previous tenant's improvements. I do not know if there is some other extraneous wiring on your machine powered by 12 volts, or if alternatively the previous tenant was a bit confused and installed a useless improvement. Perhaps he wanted an easy way to carry a battery around his property, in case he needed to jump-start a machine somewhere remote from the homestead?
Even though the OP [phillipz] hasn't been back for some time, I think I should clarify a few points about this setup. Grumpy, it's apparent that the 'tenant improvements' have been extensive here.
What he appears to have done, is to fit a battery box in place of the original toolbox, and a ring gear/flex plate and compact starter motor [probably from an outboard/marine engine].
The starter's Bendix spiral drive housing and solenoid are visible, but the motor is concealed by the corrugated rubber cover.The ring gear/flex plate has been bolted up to the Honda recoil starter cup, and a bracket constructed to mount the starter motor.
Of course the battery would run as 'total loss', i.e. need to be charged by an external charger. The socket mounted on the left hand side of the battery box looks to be the connection point for that.
It looks to be a 'cigarette lighter' type 12V socket, rather than the superior ISO4165 [aka Hella/Merit] design.
All a very Heath Robinson way of going to an electric start ride-on!
