Today I was going to clean and oil my air filter on my YZ 426 I bought last month. When I puuled the seat I was shoked to see a filter that crumbled when I touched it. When I bought the bike the dude told me how precise he was with maintance. I'm worried what all I sucked in to the motor. I'm surprised at how well the bike ran with it. Might explain the poping I had when I let off the gas. Looks like I won't be riding this Tuesday.