Okay so this isn't your typical Honda 300 4x4. It's been in my family since it was bought brand new by my Grandpa. It's always been taken care of and never abused. It was passed down to me a few years ago and I've mainly used it for deer hunting and the occasional ride. It has some dirt devil tires, the back tires are almost new and the front are about half tread. Earlier today I decided to take it out and it runs great.It rides good when it's on a flat surface but when I tried to go up a hill, it wouldn't. It won't even go up the smallest of hills either or my driveway. It's like the front and back tires on the right would spin but the ones on the left wouldn't. But if the front end was lifted up then the front left tire would spin so I don't know, maybe I'm wrong. If anyone has an idea on what could be wrong that would be great because I really need the help. I don't know what's wrong with it. Thank you in advance.