Well I changed the oil in my 450 the other day and found alot of sand in the filter and filter housing. Upon further inspection the used oil was also contaminated with sand. First thing I did was check the air filter a seal, all good there, the breather hose comming from the head checked all clear as well. I was baffeled about where this sand came from. Well I called up my riding buddy who also rides a 450f and he said he found a bunch of sand in his motor too! I honestly think some greenie put sand in our motors while we were grabbing lunch at the local spot last ride! It's too weird that both bikes suffered the same fate at the same time! Well now I have to tear the motor down and inspect the damage, I'm thinking of replacing the 4 box with the wr unit while its apart. Now my question, dose anyone have a list of the wr tranny parts with part numbers I'm going to have to order? Sorry about the meaningless post, just wanted to vent. Thanks in advance.