I have a '91 GS500 and I think the levers are somehow worn out.  They are loose in the sense that you can grab the ends of the levers and move them up and down through a range of about 1 in (2.5 cm).

I looked on ebay and saw that there appear to be plenty of inexpensive levers out there but maybe you can help me figure out which levers are good quality.

Edit:  I am guessing that the levers and the perches have to be replaced... but do you think that I should try just replacing the levers and the fasteners?

My levers also have some play... Not enough to affect their function though. The perches could be replaced, but I don't think it's necessary unless you're really noticing it/its messing with your levers.

I've actually ordered a pair of "CNC Levers" from ebay... They have shorties, and regular, and they're adjustable. I've heard nothing but good things about them from people who have been riding for years