I let my brother ride my 426 today and after he was done riding, I noticed this grayish liquid on the side of the swing arm. At first I thought that it was coming from the airbox drain tube, but when I took off the filter there was nothing. I then though that it was shock oil, but there is no splatter on the spring, plastic or sub frame. and its not gas because it doesn't smell like it. So what could it be? Im stumped.