I changed the oil today on my 2006 YZ250F and was in a bit of a hurry(1st mistake), 2nd mistake was I only put the bolt at the top of the oil tank in figer tight(HUGE MISTAKE) I rode about 20 minutes hard and I heard a funny noise so I pulled off and shut the bike off about 15 seconds after hearing the noise. I looked at it and realized the bolt had came out, next I drained the oil and about 150-225 ml of oil came out(in total), next I checked the oil filter and there were metal shavings in it, not a lot, but defenitly noticeable. The water level wasn't low(I guess it didn't get too hot) I filled it back up with oil and rode it for another 1/2hr and it seemed perfect, no funny noises. I'm going to drain the oil and check the filter again tomorow for metal shavings. Now my question is, what part of the motor are those shavings from? And any recomendations about what I should do. I think I have poor luck with my 4 strokes, on the last one my water pump seal went and all the coolant leaked out, frying the top end. Thanks, Ian.