Hobbits are notorious for fuel flow issues. Clean your carb a few times and run a feul filter first. If you run outta gas your gonna sieze.
Then if you are sure you get good flow all the time, next step is check for air leaks at your pipe.
Then if this is still happening next thing I would suggest is something Ben from WestCoast Mopeds told me about the Hobbit Metra rings. They tend to be a tad bit off. He said to sand down the area on the dyke ring where they meet/close together. He said they dont close all the way and need to be saned a bit to close properly.