did first oil change (after freebie at 600, now bike has 2100). Ordered filter, crush washers, picked up four quarts of Mobil 1 15/50. Seems simple enough except I didn't find the pre-filter, or screen, when I removed the temp sensor plug, the one on the side..............thought "Gee, wonder where it's at??" Then I thought, "Golly, could my trusted dealership have forgotten to put it back??" Accidents happen, I"ll call tomorrow, but I'm wondering if I need to get one??? I've read that it filters little metal flakes out. Also, I started it up and let the oil run through, seems to 'clatter' a little bit louder???