[Capt Kirk]

I'm sure there are people on here that have experience with this...I don't. I left mine 6v pos ground. I always had a...lets call it...laxidasical crank with a script battery. I got tired of that and changed to a 6v Optima battery. I didn't change anything else at that time and I swear I could drive to the store on the starter alone! As for your case, logically you'd assume that putting twice the voltage to a motor (that wasn't designed for it) is going to fail. Might fail tomorrow might fail next week or you might have one that will last...who knows. I personally want a little more comfort with dependability because "Murphy" is always around and there's no reason to give Murphy an advantage here. Get yourself a 12 volt starter and make things "right"... feel comfortable in knowing that if something fails it's not because of you pushing the limits.