Just wandering if you found the cause of your problem? I have a 2017 Husun Vector 500 with similar issues. Thought maybe I had bad fuel, but have ran a new tank of fuel and still have the problem, runs Ok when cold but after it warms up, it sputters and bogs down when accelerating. Also has a bit of backfire going on when you let off the gas pedal as well.
Thanks for any help you may be able to provide.