I have a DF70 Suzuki (2005) It drops from 5600 rpms to 5200 rpms after running only a mile or two. When this happens I also notice that there is oil around the air intake. I am not sure were it is comming from or what is causing this problem. The motor runs fine if I keep it at 50000 rpms or less. Any suggestions or help with this problem would be great.