I had a GS-500. 99% of spare parts of GS-500 available in markets are all used. Importing brand new parts is too expensive and GS-500 being such a old bike is not worth it. My rule is if you want a higher CC bike maintain and keep it properly. Don't install used spare parts and keep it running for showing off. If you can't install proper brand new parts. Just sell it. I sold it and bought a brand new CG-125 euro 2 and my life is now tension free.