Count the teeth on the flywheel, not the starter pinion. A 6V flywheel has 139 teeth- - - -a 12V flywheel has 168 teeth. The 9 tooth pinion gears on the starter drives have a slightly different pitch angle to match up with the flywheel.
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
Love your enemies and drive 'em nuts!