Ethanol and 2 strokes dont mix well to begin with. To run ethanol you have to richen the jetting, thats a rule, not up for debate...You literally need more fuel intake when you run ethanol. But semi-fixed and fixed jet carbs...dont have thast option, so on Ethanol, modern 2 strokes run lean...lean = hotter, more rpms, less lubrication...which isnt good.
Now, Husky and Stihl have gone to Strato-charging many of their 2 strokes as a way to pass C.A.R.B. Tier 3 emissions standards...Stratocharging is basically a 2nd air intake in the carburetor that, at full throttle, opens up and essentially blows straight air into the cylinder, through the piston ports to prevent unburned fuel from exiting the muffler...this idea WORKS...however ive found that it seems to run the engines even more lean than they already are. FOr instance, people were getting 2-3 seasons out of non-strato charged poulan wild things...the new Strato-charged versions arent lasting a single season before the pistons are scorched.
Husky has had some problems with casting flaws in cylinders...pores in the cylinders open up and make problems.
Stihls...well, they arent what they used to be for sure...The 362, 441, etc...I dont care for them, the plugs tend to come out pasty white..makes me nervous, and I dont like the torque curve on the new engines, very top heavy.
I prefer ECHO..for everything. No stratocharged engines except 1 model backpack blower, that is a rebadged Shin-Daiwa design.