I have a fair amount of experience fixing Tao Tao ATV's and no-name pit bikes, from the larger 125cc clones to the little 2-strokes. Here's what I have to say.
The Chinese have no concept of making a complete line of parts, with part numbers, revision histories, parts break-out diagrams, and parts support for many years. Manufacturers will make multiple minor and major mid-year changes with zero documentation. Parts for the TaoTao's (one of the larger US brands) are a crap shoot, even when ordered off of the company site. You can try matching number/color of wires, bolt hole locations, etc. off of eBay and Amazon, and the vendors will then have no compunction against sending you something that looks different and doesn't fit, and then just tell you "oh it's the more modern revision." Well of course it is, but that doesn't change the fact that it doesn't fit.
Like on carbs... many are non-serviceable, I'm not talking about covered idle screws, I mean air and fuel passages pressed shut and inaccessible to cleaning, things stamped or peened into place, etc.
For example on the parts issue, I got a carb from a major site specializing in TaoTao ATV support, and the float bowl came rotated 90 degrees. Support (US based) said it was on me to match the carb, they had pictures on the site. I sent them pictures where the new bowl position interfered with the intake and could not be mounted, while my old carb matched their pictures. After much back and forth and arguing the vendor realized there was an unannounced factory change on the same part number he'd been ordering for years, and relented and sent me an old-stock one he had. THIS IS NORMAL.
The electronics are wonky. I had a CDI that worked when it wanted to, would take random time-outs. I ordered 3 exact replacements, pictures matching pinouts, the last one from TaoTao direct. All didn't match what I had. THIS IS NORMAL.
I've heard some brands (CFMOTO) do a better job of supporting their US customers on parts... but keep in mind they are at the mercy of their suppliers, who no NO PROBLEM switching it up in a totally undocumented fashion.