Motorcycle Questions? Ask a Mechanic.
Hi, I’m Louie. Sorry you had to wait awhile but I’ll do my best to help.Initially, it would appear to still be a carb issue. The simplest try would be to bring this to the attention of "The Carb Shack on Ebay" for a redo of the "...carb rebuilt..."
On the other hand, if considering a DIY (do-it-yourself) repair approach, then proposed preliminary checks (if have not been done):
A friendly suggestion; take pictures, before & during dis-assembly......lots of pictures.
Sorry to hear on what you found out about the rebuilt.
Still, check the burn colors of the spark plugs as it would determine if the fuel mix is rich or lean. Equally, it would would also help us verify possibility of a vacuum or air leak.
Additionally, please ensure that the air box/filter is installed correctly; i.e. fitted with air entry only through the designated air box opening.