The day i picked my new bike up the carb ran gas out the drain hose I was in a hurry so i took it with me i will clean it when i get home carb did not stop dribbling after clean and float level set. Second carb tear down gas is by passing the float seat in the carb body by the oring. The oring is not damaged just to small or the machining on the carb body or grove on the float seat is to deep this causes the fluid level to be inconsistent I found a larger oring this cured my problem . I bought a used carb off a 2017 tc250 same carb to bore out has the lose float seat also . I have read about lots of jetting problems with this carb a two dollar oring fixed mine I wonder how many carbs have been replaced with A lectron for this two dollar problem.The parts break down does not show the oring hope this helps others with this problem proper jetting is not going to happen with a internal leak. This carb is used on 250 and 300 hus and ktm 2017 and 18 and maybe others.