I致e kind of turned this original problem over in my head, what caused the cylinder and piston scoring? The general consensus seemed to be no oil in the fuel. Possible but I keep my 2 stroke fuel in a 2 gallon can and the only other gas in a 5 gallon can. I have several 2 stroke engines, a lawn boy, weed eater, leaf blower, pole saw, so if I just forgot the oil, I would think I would have burned one of them up. My son used the saw some at my place, he could have put straight gas in but it痴 awkward from the 5 gallon can. I am almost positive I didn稚.
So several years ago I started using Amsoil 2 stroke. They SWEAR you can run it at 100 to 1 no matter what it is suppose to be. I did this for a while. I don稚 remember how long, maybe a year or two. The chainsaw is the only one of my two stroke stuff that gets used hard. After a while this didn稚 feel right so I still use the Amsoil stuff along with the Stihl oil but always at 50 to 1. This all took place several years ago but my saw had been running bad for a while. I致e also noticed Amsoil doesn稚 seem to be pushing the 100 to 1 thing like the used to. So did I ruin my saw by running 100 to 1 Amsoil mix?
used to do the work on my Brothers YZ dirt bikes when he raced, early on we ran Klotz synthetic, he wanted to go trail riding 1 day no klotz.
A friend lent him whatever mix he was running and it gummed up the piston cylinder and lost compression.
later had just rebuilt my Husky 250 WR dirt bike, (fully broken in with several full day ridings) brother borrowed it without asking...
Ran out of the Bel Ray MC-1 up in the woods, I was running (and still run in bikes and saws) a logger gave him whatever mix he was running and it burned up the Husky including breaking the ring and scoring the cylinder.
Most these oil mix companies say they are compatible but i do not ever do it anymore.
I just order up multiple bottles of MC-1 and run it just over the recommended 50 to 1 @ 45 to 1 almost no smoke and i have always liked the way it smells.
anyway a big believer in not switching out the premix oils. Going to stick with MC-1 even my old McCulloch Promac 700 likes it. i don't have any Auto tune or computer controlled 2 strokes, If I did I would not run the MC-1 in them because for newer 2 strokes they have another product.
Amzoil is REALLY good stuff for sure to.
I would never run any 2 stroke that lean "oil to fuel wise", of 100 : 1
If nothing else I would think it would affect the fuel viscosity enough to make tuning the saws Hi and low needles more touchy.