Sounds like a fuel starvation problem as its driving then dying. Do the usual stuff 1st, new sparkplug, clean air filter & clean carb.
If your scoot is still going shite then with the engine running, pull the petrol tube off the carb & check for a good fuel flow. If you don't then it's probably a faulty fuel cock (like a petrol pump), blocked petrol filter or fuel tank.
Steo
November 2009