I didn't have any luck with the 4 cell packs, but then again my motor has never been fired. .......until tonight when I installed the new battery that made it here in ONE day from California! It took a few turns to get it going since I flush the carbs with a little carb cleaner before adding gas. Didn't hesitate a bit! My battery is the same capacity as ffjmoore's. Nice to hear the 850 roar to life!!