[DW]

I'm not great with the pre 95 bikes, this is definitely one for the rangerman.
I didn't even know LI existed. I always thought the LC in ktms stood for liquid cooled, but they did make an air cooled Lc back in the early 80's.
The gs 250 were an awesome bike in their day. But being so old now I'm afraid you're probably just opening up a bag of worms. Their weak points would be the ignition systems and the casings around the water pump area. Your other issue would be trying to source parts. I wouldn't be fixing it up to ride it often. I would be fixing it up as a classic or vmx. If you're wanting an everyday ride, I would get a later model with much easier accessible parts.