mrfartsalot

I have a 1985 moto 4 200 the rings aren't all that good and it has a knock but it ran great i left it outside in 20 degree weather for a couple of hours and it fired right up no problem and after a minute of it running it died as if i shut it off as if using the kill switch to kill it but i didn't and it has spark and compression and spraying carb cleaner in the cylinder didn't start it I am out of ideas any ideas of what it is?