The user manual is posted on canamoffroad site. If it was mine, I wouldn't trust that the previous owner did any maitenance and go through each item. At the very least, change the engine oil, the gear oil, check your air filter, check the brake pads and change those if needed. Check the coolant which is probably fine. Somewhere on this forum you can get details on checking the valve timing or you can spend big bucks at the dealer and have them take care of all of the above. The shifting thing is normal. They do not shift as smoothly as polaris.