Judging by all of the carbon and the blue smoke from the exhaust I say that the rings are worn out and the engine has low compression. I would imagine that the valve guides are shot too. Also around 1:00 I can see that the deck is cracked and rotten. I would do a follow up video of you compression testing the engine and honestly, after that just salvage what you can off of it unless you want to do a rebuild video.
SO YOU DID THE CARB NEW GAS ONLY THING IS FLYWHEEL KEY IS BAD =TIMING OFF REPLACE /CHECK FLYWHEEL KEY
I usually just do a valve job and grind stems as needed
i would do a good carb clean and maybe even fresh gas.
Check for balance on the blade
Judging by all of the carbon and the blue smoke from the exhaust I say that the rings are worn out and the engine has low compression. I would imagine that the valve guides are shot too.
Also around 1:00 I can see that the deck is cracked and rotten.
I would do a follow up video of you compression testing the engine and honestly, after that just salvage what you can off of it unless you want to do a rebuild video.
Try adjusting values first and usually it will fix it and stop burning oil