Are we talking AC motors? To power a mower you'd need some REALLY hefty motors, probably something like 3-phase. If you're talking like twin 5HP motors you'll be looking at a MASSIVE amp draw for 110, so you'd probably be better off with 220. Even with 220 we're talking about 20-25 amps (looking at northerntool only one is a 110/220 and they don't list amp draw for 110. But it's probably safe to assume it's 1.5 - 2x as much). 7HP = 36A & 10HP = 43A. And you don't even want to look at the prices of them new!
Then you have to factor in that these guys can't get wet, even damp really. And you wouldn't catch me with 220v underneath my butt! You'd have to also figure out a PWM circuit for speed and steering. And then you have the inefficiency of using a gas motor to power the electric drive.
IMO, and it's only my opinion... If you really wanted electric I'd check out scarfing electric golf cart parts. You'd need a hefty bank of batteries - but from personal experience those things WILL move right along. The motors are already waterproof, and it won't hurt *most* of the electronics if you got them wet or muddy. I have an electric golf cart, and I've had it buried up to the seat in water and it was still moving right along (and I didn't get zapped, although I thought I was going to). You might be better off using the same concept you have now (one motor to a differential and braking the opposing side). If you did this you could run a simple DC to AC inverter to power stuff (or still have a generator and it could charge the battery bank also), and you could get some solar panels to make sure the batteries are always fully charged.
Now that you've got me thinking about this, I have my electric golf cart that's been sitting for the past 10 years waiting for a restoration... Maybe I'll make it into a track drive...
