2004 yz450 on the end of the shift can there's a small brass contactor for the neutral switch. When I disassembled my engine I noticed it had an oring on it that didn't look quite right. Is this supposed to be that large and what's its function. See picture below. 3rd question is other than the crank bearings and the two that are sealed on one side, are any of the rest of the case bearings directional?