Re: Bugey Starter Switch with Gear Reduction Starter
I've never worked with the gear-reduction starters, but I can tell you this much: There are basically two kinds of starters. Simple motors, like the original Spridget starters, and ones with a built-in solenoid, like my Porsche 912. I don't know which of these yours is.
For the simple motor you just connect it like the original starter.
For one with a built-in solenoid, you need a large, high-current (i.e., thick) cable from the battery to the appropriate lug on the starter, and a second wire to fire the solenoid. This second wire should go from the battery, through the pull switch, to the appropriate terminal on the starter. This wire doesn't carry high current, but it's usually about 10-15 amps, so you'll need #12 or #14 stranded wire for it.
If your gear-reduction starter doesn't fit either of these descriptions, it's something I don't know about. If that is the case, it's uncommon, so there should be some kind of information with the starter, or otherwise available from the manufacturer.
As usual, be careful. You're dealing with a lot of current, so disconnect the battery while you're working on it.