I've got the XYZ 26cc chinese engine, maybe the same as yours just different name, but I've had excellent results. Granted it does'nt start right up, requires a few more flips, but it does hand sart and never stalls. Its not the most powerful 26cc out there, its swinging a Xoar 17X8 at 7300rpm about 700rpm's less that I expected, but it hauls my 18lbs. 1/4 Cub around quite well. It does have the RC Excell ignition with the chinese knock-off Walbro carb. Dont know if it matters, but are you running a real NGK CM-6 plug? Are you sure theres no trash in the needle passages? How about the carb filter, is the screen obstructed? How about fresh gas? Other than those I dont know. Is it under warranty, can you send it back?