Ive recently bought an 01 wr 426 and the previous owner had the engine rebuilt. But it it looks like he never botherd to change the oil,and it was really black and very metallic. the oil filter was fairly choked up with metal fillings as well. So i also cleaned out the oil filter in the frame just to make sure, and nothing much was found there. Have any of you guys ran flushing oil in there motors or is this a bad idea?. Or should i keep flushing it with cheap motor oil . The motor has about 4.5 hrs use on it according to the previous owner. Any feed back welcome.