really owned stihls for 30 years never seen thisBy the way, most people don't know there's a winter/summer mode on some chainsaws. I stumbled upon it when I was modifying the muffler on my Farm Boss. Had to dig out the manual to see what it was. The sun/snowflake symbols suggested what it was.
It's a little plastic piece that routes warmed air into the carb for winter mode, blocks the warm air in summer. Around 50F is when you swap.