I have a '94 XR600R that is sounding pretty noisy. Sort of a clatter from inside the case it seems. I've been nervous about taking it on long trail rides since it sounds a little ill. My question is, if/when this trusty motor gives it up, what are the most-likely symptoms or signs? Any guesses about the noises? I haven't taken it to the dealer to ask just yet, so your info is appreciated. Ever kill an XR600?