Any bike needs to be assembled carefully. These bikes need more care, even removing parts that were "installed" before they even got to the distributor.
Fair warning to ALL china bike buyers... If you don't want to build and work on a bike, go to a big 4 dealership.
Exceptions are some CSC dealers, and known brick and mortar shops where you have a service department.
I have witnessed "expert" mechanics using power tools to "thread" bolts, only to have them go sideways and destroy the threads. I have watched youtube videos where "expert" installers actually break the plastic expansion rivets on molding plastics during the build before the bike is even out of the crate
Again, if you don't want to build the bike, or you don't have time, do NOT buy a crate bike. This includes carb tuning, chain maintenance, front axel, brakes, controls (levers and other handlebar mounted controls). Wiring and battery routing, installation, zip strip securing, waterproofing, plastics installation.
There, you have been warned