I'm getting a small amount of oil in my airbox from the crankcase tube that goes into the box. Actually it is a small amount of smoke and the oil is in the smoke. I don't have the small little filter that goes where the crankcase tube comes into the airbox should I be using it? The compression is at 150 and the manual says it should be at 185 is 150 to low? Is it normal to be getting some smoke in the box?