I bought a 2007 CRF250 about a month ago and got to ride it for the first time today. When I started the trans and engine oil were at the proper levels. After about 30 minutes of riding the bike started to smoke pretty badly and there was oil all over the swingarm that was coming from the airbox "drain??" When I go home and checked the oil levels the trans oil was very low and the engine oil level was really high on the dipstick....like I had added about 1/2 a quart of oil to the left side. Is this because of a crankshaft oil seal on the right side? Appreciate any advice. Thanks!