While the thread is likely only about the GXH50 & clones, I think it's somewhat important to note that not all models of cloned engines by the same manufacturer are of equivalent quality... clones are a very tricky business sometimes lol
Lifan a good example - while not bad at all, their cloned utility motors are generally not nearly to the same quality & specifications (aftermarket parts interchangeability) as their Honda CRF clones. The reason for this is unlike the copied utilities, there's been many reports claiming Honda had actually contracted Lifan to produce factory authorized replacement parts for their horizontal CRF type engines, Lifan then producing entire engines to the same specifications.
Thus, that particular model line is about as close you can get to a Honda for a fraction of the cost - corporate business ethics notwithstanding lol
True or not (Honda ain't saying, surprise surprise) a general rule of thumb when considering clones is to assume if it looks close, but not quite the same - it isn't the same & odds are even quite different where it counts. Research a clone's parts compatibility with it's branded equivalent, if the majority/all are cross-compatible then it's likely it's a direct clone & very close to the original's quality excepting some peripherals - for the CRF50 Honda/Lifan example this would include basic ignition components, starter & some fasteners... not partic an issue as they're all replacable w/Honda parts if desired.