On my new (to me) 94 GS500 it looks like the rear suspension is adjustable.   I don't have an owner's manual, the Clymer manual I got with the bike doesn't mention this though.  Anyone know how to make this adjustment?  Thanks

Matt

I am not a pro mechanic , but I think the stock is not adjustable

my 91 appears to be adjustable, looks like there's a barrel adjuster on the bottom, and it's numbered 1-5, as well as a tool in the tool kit that fits right on it to twist it, but it is really really hard to get to, so put it up on the center stand and just be patient i guess, anyone know for sure which way is stiffer? i'm gonna assume 5, and is there a mark anywhere to let me know where it's at now?

This topic has been done before but not for a while as so many of us have replaced the rear shock.  Does this tell you something?  The stock shock is adjustable for spring preload only.  The collar is at the bottom and is awkward to get at.  On my 2001 I could only get it if I approached from the right and angled the spanner.  I could only get half a notch at a time so I had to hold the collar and reposition the tool to get the other half.  Took me nearly half an hour the first time I did it.
Replacing the stocker with another is a really good idea.  There are new aftermarket ones around (I have a Hagon from England) but most guys in the USA go for a Katana 750 shock.  There are numerous threads describing the installation and which year models will work.  Good luck.

It's adjustable, and it's tough.  I tried 3 times before I got the word on how to do it from this list.  Put the bike up on the center stands, and approach it from the rider's right-hand side.  I laid down on the ground and pointed the wrench handle towards the handlebars.  One click at a time, took about 15 minutes.  The higher the number, the stiffer the setting.  I cranked mine to 7, and noticed an improvement in the ride.

John.

Use a driftpunch and a hammer.