Pull you air filter off and with a light look into the throttle body and see if it is absolutely shiny and Clean. If it has eaten dust you will most likely need more than rings .

 

Check your intake for signs of dirt and debris getting past the air filter. This is a fairly common issue on the 800 motor. Dirt gets into the engine and scores up the cylinders allowing oil to work its way around the pistons and into the combustion chamber. Using a heavier weight oil might help as well. The combination of synthetic oil and fuel injection does not product the blue smoke that is a typical sign of burning oil.

Here is another thread about oil consumption as well.

http://www.rzrforums.net/engine-drivetrain/74247-burning-oil.html