Today I assembled the second alternate air/carb heat unit. Fitting the internal butterfly style valve is a somewhat slow, methodical process.
The valves are held in an "open to cool air" position with a small spring. The photos attached show the two units with the springs and cable ferrules installed. The third photo shows the left unit fitted onto the carb.
The air that is routed to the warm air intake is heated by the muffler. A shroud is fitted to either end of the muffler unit. Air flows through the shroud and hence around the muffler, then through a 2" corrugated tube to the carb heat valve. I installed the shrouds on the muffler today as well.
