Yamaha NEOS 100 newbie

Hi everyone I'm Jordan and I'm a complete bike virgin so please forgive me in advance. I have YN100. To cut a long story short it toom a trip to the mechanic and he descoved that there was a sock around the air filter (previous owner must have done this) after removing the bike ran fine for a few days. I've replaced the air filter and once I get the bike going and has let her warm up once I accelerate it will big out it doesn't matter what throttle I'm at it picks and choses when it wants to bog but it will do it every drive? Any idea what's going on? Again I'm sorry if I sound like a complete ideot thank you everyone

 

Sounds like the carb is all out of tune.
But first try changing the spark plug.
Is it a "sports" filter? Or the original airbox?