I had a problem with my Puch. 78 Newport. It always bogged down at full throttle.
I tried cleaning the carb first. It was a mess but that didn't help.
Got a new exhaust and removed the air box.
Then I tried changing the position of the injector needle in the carb.
Nope, not that.
Then today I took apart the carb, AGAIN. This time I removed the jet, sprayed the crap out of it with cleaner, and ran a wire through it. It was a little cruddy but even a little causes all kinds of bullshit. A good way of getting a better look at it, since the jet is about the size of a pebble, is to use binoculars turned the other way so as to magnify.
Put it back together and she's running right again.
Could this be your prob? Maybe, it's worth a shot.