Here's a new one on me......I start my Savage SS and it runs for about 10-15 sec. still and doesn't stay running. I tried leaning the engine out 1\8 turn to no avail. When it's running, I feel something hit my bare foot, and I lean down to pick it up and it's this (a plastic-like shaving):

It looks like it's coming from this wheel (big wheel on underside of Savage):

Is this the brake disc, and shavings are coming off of it?? If so, I don't know why because my brake isn't engaged. Also, when the truck is off the wheels spin freely. I'm confused...