I just went to fire up my 03 yz450 and it started smoking like crazy...It ended up there was oil on the exhaust causing the smoke, however the oil was spraying out of my cylinder head by the camshaft exhaust?( a vent on the upper right hand side of the head) onto the radiator then down to the exhaust pipe. I checked the oil level and was not missing any, fired it back up and rode it around a little bit and as I expected, the oil was still coming out. After it cooled down, I started it back up and put my finger over the camshaft exhaust and it quieted the engine up a little bit but continued to coat my finger in oil. I rode it yesterday and didn't notice any problems. I am a newbie to the forum and not a gearhead either. Any advice would be greatly appreciated. Thanks alot!