Try to find a part number on the starter, and it will be pretty simple to cross-reference it to see which voltage it's designed for. If, indeed it is a 12 volt item I've got the 6V flywheel and starter you would need for a swap, rather than doing a 12V conversion.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
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