I'm curious to know if anyone can tell me about this phenomenon--I'm new to riding and not very machanically inclined (yet). When my '01 GS is in neutral and I rev it a little bit, it tends to fall back to idle. By that I mean that if I bring it up to 3000 rpms and hold it, it will give a little cough and drop to 2500 or so, then again down to 2000, then again to 1500 etc. It just drops to idle, it doesn't stall. If I let go of the throttle is just stays at idle, and I can rev it up again.

It doesn't do this when the gear is engaged, ie I can maintain speed by holding the throttle steady. It only happens when it's in neutral or I've got the clutch pulled in.

I'm not really worried about this, because the situation in which this happens (revving while not in gear) isn't a situation that occurs in real riding. But I'm curious as to what might cause it. I've read that the '01 models were jetted lean, and I know that the previous owner had it rejetted to make cold starts easier. I assume that that is the cause or at least connected, but if anyone has experienced this and/or can give me a more technical answer I'd appreciate it.

are you sure the bike is fully warmed up? the gs is extremly cold natured

Ah well, that's a very simple possible explanation. I thought the bike was warm (it was definitely beyond the point of needing choke), but maybe it wasn't totally completely warm. Naturally I've only thought to check this at the beginning of a ride, and not at the end.