I was starting my 01 400 EXC to warm up for a race and it was making a terrible knocking noise. Luckily, a friend talked some sense into me, and I raced his bike and brought mine home to inspect. One rocker arm roller is oily and rolls fine. The other is dry, burned, stretched, out of round, and missing some of it's needle bearings. It appears that the oil line is designed to shoot oil right down on top of both of them. I am wondering if my pump is weak, or the line plugged, but then shouldn't both rollers be dry? Help somebody. Also, since my cam is ruined, should I consider an after market cam, or go back with stock? Thanks.