Really could use some input from all dirt riders but this may be specific to XT350. First Problem: Bought a 96 XT350 last Oct 09 with 10K miles. The oil filter/screen had a lot of nonferious(non magnetice flakes and black speck on it. And every time that I have removed the filter. Second problem: Knocking in the motor. In short I found that the right side main crank bearing sits in a steel ring that "appears" to be formed or cast into the case casting. The bearing is good but this outer ring is moving up and down about 0.018" and this outer ring rotates a total of about 30 degress. Best guess of the metal and black debris on the oil filter is clutch. All clutch plates or in spec. Best input so far on the main bearing ring is, "ceased bearing, hot bearing ring that weakened casting that allowed movement and has banged its way out to .018". Repair options???? Tried shimming arond the ring and locktight 640. This worked for 25 miles then back to knocking again. Last weekend, split case and removed all shims from the sump. Two new case haves? 700$ Ebay right side only Case 50$....Will this work?? Will the cases seal?? The manual says both cases need to be replaced in pairs because they come as a machined fit pair. Does that mean all borings and recesses or just the fitup center seam seal???? this is a no gasket seal. Note: I have bought a 98XT also, 7400 miles, and it does not bang BUT there is some of the same debris on the filter.