I'm working or resusitating the se-wet vepon (tm), and had the top end apart to survey the damage. It *was* a GS500 engine that I floated the valves on with a too liberal a use of throttle. Bent vavles, nice smiley faces in the pistons, the usual results... One thing I noticed was that most of the valve spring pairs (the outter and inner) were "kinked" together. They took a bit of convincing to come out of the head, and had to be twisted apart. Never noticed that before when playing with the vavles. Can you "squash" or otherwise distort valve springs?
Floating a valve means you heat the springs to a point of failure and they no longer can keep up with the valve action. Valve float can be slight or real bad sounds like yours was on the very bad side. The springs get hot from use and over time they get softer..
