In general, Stihl has 2 types of chans ANSI low kickback and non-ansi chains. Think the low kickback has a green link, and non-ansi has a yellow link.
.325" and .63 sounds about right for my 2011-ish MS261. I'd buy nother one. Only Issue I ever had was an ignition pack dying in 2018 or so. Cut about 5 or 5 cords for 5 or 6 years. Don't heat with firewood anymore. Just cut camp wood, keep food plots clear, and maintain about 2 miles of trails. Never cleaned the carb yet either. Non-ethanol gas and silver stihl oil cans. Used to make 2 gallons with the 2.5 gallon mix container. Now I only use 1 gallon ones and do 1 gallon on the money. Always fresh gas from the pump.
Several camp members have the farm boss. For almost half the price its a good saw. 261 has about the same power it seems, just weighs less with all the magnesium parts.
2 strokes you don't change oil, you change spark plugs instead.
I abuse my saw alot too. Use it as a substitute to an excavator. Chop trunk roots so I can tug them out. Lots of old dead wood too. I go through bars often and always have a new bar and chain with me.
Been there! Lol
