I have a '02 WR250F and have searched the forums for some leads with little success. I bought the bike used from a fellow who road only the track and was quite meticulous with maintenance. I road it maybe 12-15 hours after purchase and just struggled through my first oil change and pulled the oil filter, which leads to my question... not knowing how long its been since the last oil filter change, what is, if any, a normal amount of debris or metal 'filings' in the filter? Further, how frequently should it be changed? I read in another forum about every 15 or 16 hours. Can someone help me out? Cheers.