So my 1986 CR250 has this noise coming from the cylinder, it's not a "cling" or "clack" or "ping" it's kinda an air-y metallic sound, you can hear it in this video from this bike, when he gets closer to the front you can hear it better, just try to tune out the exhaust pop. Do all bikes make that sound? A guy offered to buy my bike and I said "there's a knocking sound from the engine" and never heard back from him since... I know about that whine big bikes make when you first take off, everything from sport bikes to CR250s. But what about this cylinder sound? Does this make any sense? Can you hear it in the vid?