I tend to stay away from the super cheap knock-offs and usually buy from a US-based reseller. The bigger, known sellers will ask a bit more for their version but I've found them to be more reliable with fewer problems out of the box--over tightened jet screws, twisted float bowls which kill the gasket, etc. The one thing I'd definitely recommend is heading to your favorite ACE or True Value, go to the loose hardware section and grab a handful of fiber washers to fit the main jet. Those China carbs fiber gaskets last about one removal of the bowl--less if over tightened coming out of the box. Also follow the instructions in the Tecumseh manual to re-set the float prior to installing, as it is almost always off. Most of these carbs were for fixed throttle applications, so be prepared to tinker.
