sry wat do u mean by elevation? I have cleaned carb didn't work(was a bad carb anyway) and also put in new carb also cos old 1 was leaking petrol ,yes its not watercooled sry forgot to mention that.

 

No problem. Elevation as in Sea Level is 0 (zero) all the way up Mountain level. The elevation levels can affect how your quad is jetted. I know more so on a 2 stroke. Since you have an old carb. Take that old main jet and drill it out just a little bit larger than stock. Install the drilled main jet and see if this helps in heat.

 

Check valve adjustment. Intake .002. Exhust .003 gap

 

I would check valves as well. Also MIGHT be your gas tank vent is clogged or even some dirt in the float bowl. Unfortunately, it sounds more like an electrical component that is overheating and failing.