I have an overheating problem on my 1980 kz 1300 i think its the thermostat but i dont wanna buy a new one if that is not the issue is there any other solutions to this problem or is it the thermostat?

The thermostat will only cause overheating if is not opening - or not opening at the correct temperature. Before replacing it, you may want to rule out some of the other possible causes of overheating: Bent or otherwise obstructed radiator cooling fins, contaminated or insufficient coolant, clogged radiator, incorrect temp gauge reading, inoperative cooling fan, defective radiator cap, etc.
Check the above things, then ask yourself: Does it overheat when riding at highway speeds, or just in slow riding conditions? Is it really overheating? Coolant temps that exceed about 250F is cause for concern. Coolant temperatures which do not exceed 250F while negotiating stop-and-go traffic on a hot summer day are quite acceptable.
If all else appears in good working order, remove the thermostat and place it in a pot of water, over the stove. With a thermometer handy to measure the water temperature, begin heating. You should be able to see the thermostat begin to open by the time the water gets up to 185F - and it should be fully open at 210F. If it fails this basic test, replace it.