Motorcycle Repair: suzuki gs 125cc, overheating

Question
just bought this bike  (used)2000 reg engine seems to get very hot and after 15 min run takes about 2 hours to cool any idea s plz

Answer
Is this your first air cooled engine? Air cooled engines tend to run hotter than liquid cooled ones.

When you say 2 hours to cool, do you mean completely cool to the touch or still warm? 2 hours to completely cool isn't too unreasonable.

If you are familiar with air cooled engines and think it is runing hotter than it should, try adjusting the carb. An overly lean mixture is the most likely cause for overheating. Carb adjustment should be coverred in your shop manual.