Oil leak on a 5hp 4 stroke evinrude

[basstender10.6]

So here is the deal. Last weekend I picked up a 1999 evinrude 5hp 4 stroke that looked brand new inside and out. It runs great and pumps water strong. The engine does not over heat or loose power when running. I started to notice that when idling there was what looked to be oil or gas in the water around the outboard. And after running for a long time at a fast speed I noticed an odd smell from the motor and a blueish smoke coming from the exhaust. I checked the inside the engine and found that there was oil laying around inside the engine compartment. The engine oil level went down a little bit, but not drastically. I did notice that when I first got the engine the oil level was high but not overflowing. It looks as if the oil is dripping down to where the bottom pieces of plastic cowling meets the lower unit. I really do not know what is going on, but was wondering if anyone knows what I should do. Thanks in advance for any help