you are right this is to alloy warm air in from around the cylinder head in to the carb. so it does not frost up, on the cold days,
had to flip mine over, but i was about to throw my saw to the ground the damm thing would not start with out the choke on my arm was killing me, and the crane operator was geting pissed of as well, till my buddy reminded me to flip it over.
It was damm cold these coupple of days -15 - 20 c sorry i dont no (F) .
lawmart
play safe