It is probably pretty common if it has been spilled  

Yeah it was bumped by a car I think.  Will it continue to do so you think?

On a more serious note, I am looking at both a Kawasaki EX500 as well as a GS500 for my first bike. I have known for a while now that the EX is definately faster stock which I am willing to sacrifice. But I was searching on any possible overheating problems (since the EX500 is liquid cooled) and I came across this link http://www.mcnews.com/mcn/model_eval/NinjaGScomparo07a.pdf and I'm a little lost as to all the other advantages especially handling with a GS500?

The Ninja is ugly.

It feels awkward at slow speeds. Liquid cooled is hard to work on. Valve adjustments will be a pain in the ass because it's a liquid cooled and 4-valves-per-cylinder engine. It's also ugly.

Really ugly.

Damnit yes they look nice but when if it means the difference between looking good while crashing or looking ugly and watching the good looking bike in a mess, I'd rather have the latter.

I did a search after that and saw that there are some discussions about that article already. I haven't drilled down below to see if there was anyone that rode both of them for a while and have a good judgement about it.

I did read about the progressive springs for the front and am looking into it now. Lots of reading to do...

Its generally accepted that the ex is a bit faster and is a bit more of a pain to work on and maintain. Neither have overheating issues and both, being nudget starter bikes, have issues with soft suspension and with funding sticky tires in the right sizes.

The differences though are marginal, especially to a new(er) rider. They both make good first bikes. Buy whatever one you can find at a good price.

I paid $2k for my '89... but it was in PRISTINE condition and it had 12k miles. (As well as a full '04 fairing + tank + tail)

Bike hunting has taught me a few things:

-If you like sportbikes, you won't find anything in good running and cosmetic condition for $1000.  

-Well maintained bikes hold a lot of their value due to demand and the fact that going to a dealership always involves paying waaaay more than you should.

Were I you, I would inspect the body and frame.  If it isn't rusting and it runs, then it is worth trying to haggle.

At the end of the day... an '89 GS looks and runs pretty much exactly like a '96.  (except you will have white wheels and phatty clip ons).