From the sound of the 036 in the video, it sounds like a very poorly adjusted carb, old fuel, a partially blocked spark arrester, a super dull chain, and an idiot for an operator. I wonder If the guy in the video used the classic angled back cut to finish that tree off? These people are a danger to themselves and everyone around them.
I see this garbage all too often where I work. It's aways the mechanic's or dealers fault that their saw doesn't perform. I had one guy tell me I did a horrible job sharpening his saw chains, and he wanted his chains sharpened for free. I said wait a second...those chains were razor sharp after I sharpened them there's no reason the shouldn't cut...What are you cutting? The guy said he's sawing tree stumps out. I told the customer it does not matter what chain you use or how I sharpen them, no chain will hold up to the careless sawing of stumps short of using a carbide chain.
I had another guy come in to have his saw tuned up. The saw just needed a spark plug, clean spark arrestor, a chain sharpening, a new fuel line, fuel pick up body, rim sprocket, fresh fuel, and a good carb adjustment. the saw ran like a champ. The guy comes back a few days later his saw is not working good! and he wants it fixed for free. One quick smell of the rancid 10 year old fuel told me what was going on. I said to the guy you need to dump out your rancid fuel and go to the gas station and buy a gallon of fresh fuel. The guy said, old fuel doesn't have anything to do with his saw not running good. So I took him back the the shop, dumped out his rancid piss fuel, filled the tank with new fuel, started the saw. The saw spit and sputtered along for a bit, then cleared up and ran like a champ again. I haven't seen the guy since. Maybe he took my advise and bought some fresh fuel, or maybe he went to terrorize some other small engine shop. Who knows.
I had another guy come in with an echo cs-440. He whined that we sold him the wrong chain. He wanted a 33SL chain, we only had 33LG chain. Somehow he felt that even though both chains were 0.050" gauge, 0.325" pitch and 78 drivers, the non safety 33LG chain would not turn on his saw. But for some reason the 33SL could. It couldn't be the woreout/cut completely in two spur sprocket...no those never wear out. So after arguing for 10 minutes that his sprocket was shot causing all the problems, I finally was able to install a new sprocket & chain and send him on his merry way.
I could go on and on with stories about dealing with idiots. It amazes me how these people get out of bed in t he morning.
Nick