Runs fine for 1/2 mile then quits

Hi it sounds like a problem i had on a ty175 years ago what your problem is fuel starvation their is not enough fuel getting to your carbs so you emty your float bowls and the engine cuts out ,but they will be full again in thirty seconds so your bike will restart again and run for 1/2mile .You need to check you fuel tap is not blocked and change your fuel line filter if fitted also the internal fuel way into the tap remove the tap from the tank and clean it all its probley full of sediment it is twenty two years old i hope this may be of some help for you sorry about the spellings but it is late i live in oz

Check your gas tank vent cap, check your carb bowl vents. fuel filter.
open your tank and gently drive down the road and see if this helps. It may be pulling a vacuum.