I've got several gas engines of various sizes that came with the place. I think one is from a snow machine. Most are 5-8 HP. This winter I'd like to make a 4 wheeler to use around the place, for light hauling and moving garden stuff and bales. I thought a couple of hydraulic motors and a pump and two valves would be easy, then drive it like a Bobcat. Trouble is, I know nothing about hydraulics. Anybody have a suggestion? I've got 4 small airplane tires for it, they are slick and shouldn't cut the grass up on skid turns.