1987 honda trx 250x runs good but gets hot after 10 minutes and dies?

It will run good but gets way to hot and will just die

Just got the topend rebuilt a week ago. Any ideas

Cooling system issue. You might have a stock closed thermostat. I would probably start there just because it starts to over heat after 1 minutes of running. I would also check the fan, radiator, radiator hoses and even coolant.

Hi Augie its air cooled it has no radiator or fan