definitely something wrong with your clutch. take the cover, off, and take a video of what happens in there when you pull the handle.
Also, pulling the handle is 'clutch disengaged', not engaged. the clutch is naturally engaged, by pulling the handle you are disengaging it.
Thank you for the video , most people here just mumble nonsense and never post pictures or videos and then get mad when nobody can help them.
EDIT: using the stock spark plug is fine for break in, but they are crap. Get a proper spark plug. NGK BR8HS is the most common that people buy. Some run BR6HS or BR7HS (the number just means heat range).
@DAMIEN1307 swears by running an 8 in summer and a 6 in winter but I can't speak to that personally.
Also make sure you set the gap , 25 thousandths. Feeler gauges and spark plugs can both be bought from pretty much any autoparts store.