when i pour oil into my case it goes in clear or yellow/brown tint, when i drain it its silver. this leads me to believe its metal shavings or particles that cahnges the color. do yalls bikes do this to oil? i was thinking of flushing my case. i was wondering if i should flush it w/ kerosine and refill w/ oil, ride 10 min or so and then change oil again. any suggestions???