The pack is 12v and I really don't have any experience with electrical engines, only gas.
no you can't. AC motors all depend on 110 (or 220) AC. they cannot run on DC. they're called induction motors, because the magnetic field is induced in the armature. there are no brushes, and no current is supplied to the armature. the benefit is that they last longer, and don't need to have replaceable parts. so, it's back to your old lawn mower engine. your gas powered lawn mower engine, that is.
Fisher-Price battery packs are a disappointment to many Fisher Price, riding toy owners. You are probably better off considering a motorcycle, car, or deep cycle marine battery. This does bring up a set of issues that electric vehicle makers have in general: cost, weight, volume/space, and bracketing for the batteries required. The next set of issues relate to charging systems; you might want to visit a couple of automotive and RV shops to get an idea of the considerations involved in selecting a charging system of which cost is only one. It also sounds like it is time to learn more about electricty, physics, and electrical motors. I'm sure that there is a reasonable amount of information available for free on the internet. But, the library is a great source for free information too.
