[JQmile]

Originally Posted by Stubby79

It can be spun both ways.

Bearings are sealed. You can potentially pull out the seal and get at the grease and bearings inside. I doubt it's bearings though, if it's only doing it in one direction. Turn it by hand and see if it does it at a certain point, or if it's a continuous roughness. It might be something minor that will go away if you give it some run-in time on your bench.

Motorcycle batteries will only last maybe a minute or two and probably over heat and ruin themselves in a hurry, under load.

You want to be careful using only a switch...You don't want to exceed the motor's current limit (330 amps) much if at all, and with just a switch there's nothing to stop it pulling more. At least the motorcycle batteries won't put out that much for long, if at all.

Batteries are always the hard or expensive part to anything of noticeable power.

Cool thanks for the info! The Go Kart will still have the 12hp gas engine on it, so the electric motor will only be used for an acceleration boost. Doubling the horsepower and tripling the torque just sounded like fun. Based on my math I'd have about 12 minutes at 100-150amps but I could be off. I may run it electric only just to see what happens but for now the plan is just to use it as E-nitrous