First... You are mixing 2 stroke oil in the gas... right?
First thing you need to do is install an inline fuel filter in the line to the carb.
That will stop the worst crud from getting into the carb again.
Then you will have to clean the carb again... you MUST use high pressure compressed air to blast it out.
Find my post called "read this to learn > How To Fix Your Moped"
There is extensive info on how to clean the carb properly and other tune-up info to follow.
Also remove the gastank petcock and clean it.
Having to run with the choke on ABSOLUTELY means your carb has clogged passages.
Then you need to check for exhaust blockages.