It is normal for quite a bit of oil to be thrown from the exhaust system when the engine's running. Depending upon the airflow around the airplane, you can get large puddles forming in various places. It's normal to have to clean the airplane up after each flight, and after flying.

We've seen models that have literally large streaks of dark, burned oil running in large enough quantities that they drip off the model once it's back on the ground. You just pick up the rags (paper towels, etc.) and wipe it down.

If you have a lot of fresh fuel on the model, then you need to see if the tank's venting fuel overboard, or if it's being thrown from the carb or front bearing. A lot of fuel coming from the front means that the seal's gone, and you'll need a new case, crank, or both. The bearing does not provide a seal.