This is really one of the most misunderstood issues we face as hobbyists working together to get this all squared away.
6 volts uses TWICE the amperage of a 12 volt system. This is good for us over the longer haul because they had to make wiring, windings, everything capable of handling twice the current of what we use today. To a point of course. Anything requiring close scrutiny of the Power formula doesn't pass muster, however the starter is a good example of what works famously with a 12 volt system. Reason is because applying 12 volts to the 6 volt starter is MOMENTARY. You can run your 6 volt starter on 12 volts forever as long as you do not run the starter more than is necessary to get it running.
So please make sure your systems are in good shape and you can use that FLYWHEEL that is made for the 6 volt systems, and not worry about it AT ALL. Best to just get a replacement that is the exact same as the one you took out keeping the above in mind.
