5 HP Tecumseh with two chokes?
I have an old (maybe 1970's) Eaton Viking 21" snowblower, model 6722. I believe it was made by MTD. It has a 5HP Tecumseh H50. The air intake on the carb has a regular butterfly valve for the choke, but it also has a spring-loaded cover. This has a knob on it that you can push to block off the air, but if you let go the spring opens it back up. Does anyone know what this is for and how to use it?