If you have spark and compression, and a clear exhaust, and it won't fire on aero, it is probably crankcase seals or carby to body seal. I've got a Chinese Stihl clone that I have had for a few years now, 72cc with a 25" bar, and I have felled some pretty big trees with it and cut up some pretty big Ironbarks that I had pushed out with a D9, one being so large that to butt it I had to come from both sides as it was nearly three feet through, and the damn thing runs like a rocket and has never failed to start on two or three pulls from cold even in Winter so you can get good clones, just depends on how close to the original they are. Best part is the saw only cost me $89 shipped to my door!
