I had a similar problem with my engine after it had been running pretty well for about 4 weeks. It just had no power, super bad case of the blubbers similar to how you describe. Sometimes it seems like fiddling with the choke helped a tiny bit but not really very much... What it turned out was that the choke plate in the carb, the part that actually chokes it when you fiddle the lever, had come loose so basically the choke was stuck on all the way. I just removed the plate and now I just don't have a choke anymore, which is not a problem at all since i never start in weather below 35F & if I really needed to I could cover the air intake with my hand and achieve the same thing anyway. fixing it would be an option too though I guess. so see if there's a little plate sliding around in your carb, mostly ignoring the choke lever.
Make sure to follow up like other people have said about your intake and make sure that it doesn't have any leaks although intake leaks tend to lean out the mixture and it sounds like you are probably dealing with an overly Rich mixture - inspect the spark plug to be sure
Based on experience & reading I've done, 16:1 is too oil rich. It probably wouldn't cause your problem in and of itself but it's definitely contributing. For break in, I used premium synthetic 2 stroke oil at 25:1 then from the fourth thru tenth quart I gradually transitioned to about 35:1. ( I stand by it, but YMMV. A theory I read on this site says that the recommendations are way too oil rich, because when sold domestically in China these engines are off and running on the cheapest motor oil available, not even on bottom barrel 2-stroke oil, let alone full synthetic )
Take your time and solder the electrical together. once you've got spark you may even find the whole thing is solved, because flaky connections that give out enough of the time above certain RPMs could also be the culprit
Make sure to follow up like other people have said about your intake and make sure that it doesn't have any leaks although intake leaks tend to lean out the mixture and it sounds like you are probably dealing with an overly Rich mixture - inspect the spark plug to be sure
Based on experience & reading I've done, 16:1 is too oil rich. It probably wouldn't cause your problem in and of itself but it's definitely contributing. For break in, I used premium synthetic 2 stroke oil at 25:1 then from the fourth thru tenth quart I gradually transitioned to about 35:1. ( I stand by it, but YMMV. A theory I read on this site says that the recommendations are way too oil rich, because when sold domestically in China these engines are off and running on the cheapest motor oil available, not even on bottom barrel 2-stroke oil, let alone full synthetic )
Take your time and solder the electrical together. once you've got spark you may even find the whole thing is solved, because flaky connections that give out enough of the time above certain RPMs could also be the culprit