You're cutting too much grass at once, going too fast and straining the machine to the point it stalls. Not sure what the noise is, but it sounds like the deck is clogged from forced feeding.
Sharp blades, raise the deck up, mow more often and go slower.
I have tried going slower but the machine stop, is it because of high grass? is it carburetor issue?
even after I adjusted the machine higher and then going back and redoing the same area with lower lower it stop.
In addition to not knowing if the mower's engine has been well-maintained,... as said above, you are asking too much from it. Generally, your aim should be to cut 1/3 off the blades of grass. The grass should be dry. The underside of the mower should not be packed with clumps or excess clippings. The blade should be un-bent, sharp and balanced. If you aren't discharging or bagging, the blade should be a mulching type. If you come to a particularly thick area, overlap with half the previous cut again, then go back and line-up to continue.
when you hear the engine slowing down - it is telling you it is going to stall from excess load.
Is there a proper amount of reasonably fresh oil in the engine? How old is the spark plug? has the mower been damaged/hit or improperly repaired in the past? Will the mower idle smoothly or does it die? Sometimes, the screen in the gas tank has debris covering it - maybe check for that?
the lawn mower was serviced about 6 months ago, I had the gas tank replaced and air filter as well. the spark plug was replaced about a year ago.
carburetor was not raplaced since 4-5 years ago.
I will check the blade condition and see if its lose. I think the metal noise is coming from the self prop cable ring at the bottom left its making that sound.
I have used a mower in the past where the owner had sharpened the blade but kept running it out-of-balance. It actually shook bolts off the mower and the recoil starter was coming loose!
I have used a mower in the past where the owner had sharpened the blade but kept running it out-of-balance. It actually shook bolts off the mower and the recoil starter was coming loose!
If you are convinced the mower has reduced power - you will likely need to take it back to the shop.
However, whether you do that or not, the grass shown in the video would probably stall many mowers. So, do not try to cut full height/width cut when you encounter very tall grass - overlap the cut of new, tall stuff, with previous newly-cut path. Safely, make sure the underside of the mower isn't packed with cuttings.
replace any missing bolts - consider using threadlocker on them. Sharpen and balance the blade.