Well, the engine really isn't that good, it's full ow flaws. The valvestems tend to break. The Gerabox layshaft tends to break. The engine carters tend to crack. The alternator coils tend to meld down.
But Jincheng isn't the worst ... if you think the Jincheng copies are poor, you should check out the Huawei engines. (The Huawei corp. also builds the Zongcheng engines, same things, different name). Those engine are even worse than the Jincheng things are.
But not everything is bad about the Jincheng stuf. Their cilinderheads are pretty good, almost as good as Honda's. But the fun part is that Jincheng fits most of it's engines with their copy of the HRC cylinderhead instead of the standard head, and that HRC (Honda Racing Corp.) Head is pretty fast. :).