the brass screw is an air screw. it will add air to lean out your mix at low throttle. the white screw on the side is a fuel screw. which will add fuel to richen the low throttle use. if you have exhaust gauges you can tell how they work. about a half of a turn is around 100 degrees. i believe that i have my air screw set to two and my fuel screw set to 1.5 turns out. this is at 8-10k. centennial and togwotee. can make a very big difference in fuel economy and bog situation in deep snow. if your idle is to high then use the idle stop screw that controls both carbs. if you get both screws adjusted correct, you will have to hold on tight when you hit the throttle because the sled will jump out from under you in a hurry. if you want exactly what i have let me know and i will go to my sled and post it here. i run egt twin window gauges and will always run gauges because it is the only way that you can get your carbs adjusted perfect. i run about 800+ degrees at all times just off idle. this also helps when in the deep powder so you don't bog down. also put some foam over the carbs to keep them warm and snow off of them. this will also help the bogging down in deep powder. some carbs have coolant running through them to keep them warm. the foam acts as an insulator and protector to keep the cold snow off and engine heat in the carbs.
