No- - - - -the shaft diameter is different, and the 12V starter drive (not a Bendix) has a spiral drive spline. 6V is straight. 6V starters run just fine on 12V- - - -they just crank the engine a little faster. Keep the engine well tuned so you don't have to crank it for very long.
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!