I agree with PastorJim, for a adult I would think that 350 would be about minimum. I was looking for one between that and 500cc. I bought a 650 because it was a good machine and cheaper then the other used machines that was offered at the time. It has way more power then I need and I doubt if I could pull start it with the rope starter. Again, I have never needed 4WD, but I only use it in the hills and during dry weather, so far. But it is good knowing that I could use 4WD if needed. I would think that any of the American or ***anese brands would be good, they have made them for awhile now and should have worked the bugs out. If you can, get one that is fuel injected so you won't have to play with the choke and flood it sometimes. If money were no object and I wanted a new one, I would get a Honda Rancher. It is 420cc and fuel injected.