Have you tried screwing the idle speed adjustment all the way in? This should raise the idle speed to at least 5,000 rpm so it would be running on the main jet, not the idle jet. Note I'm talking about the idle speed adjustment, which holds the throttle butterfly slightly open - I'm not talking about the low speed mixture screw.
If it will not run without even more throttle when the idle speed is set impossibly high in that way, please tell us that and we can think further. If it will run in that test (without major throttle but only at high speed) the problem is in the idle system of the carburetor. Unfortunately because Ruixing does not provide any manuals as far as I know, it is difficult to move on from there in any orderly way. Ruixing carburetors are normally fairly exact copies of brand-name carburetors, and I have seen a hint on the internet that yours may be a copy of a Zama. I suggest you try to find your Ruixing in the Zama Tech Guide, which you can download here:
http://www.zamacarb.com/pdfs/TechGuide_2007.pdfPlease let us know whether you can get it to run with the idle speed set ultra-high, and what kind of carburetor your Ruixing is cloned from - then we can work on it from there.
