new bad sound

[Lou B. DeSimone]

Which noise is it? Burnt out valve? Piston slap requiring top-end rebuild? a rod ready to go? Bike sounds a lot like it used to, but loader, sloppier, and ready to break. A mechanic said he didn't know what it was, but that I better park it quick until I can take the engine apart until I find out what it is. It's rhythmic, mostly noticeable when idling, and goes away when driving. Although high end performance had recently decreased due to the need for a valve adjustment (10,000 mi.), it came on all of a sudden when I came to a stop sign. Anybody? Lou DeSimone '97 KLR650 with 33K mi