1990-1998 Arctic Cat Snowmobiles Repair Manual, Page 222Get this manual
212 The carburetors installed on these models contain several major systemsA float and float valve mechanism are used to maintain constant fuel level in the float bowlThe idle mixture system controls the amount of fuel at low engine speedsThe main fuel system controls the amount of fuel at high speedsAt intermediate engine speeds, the fuel is controlled by the needle jet and its jet needleA starting enrichment (choke) system is incorporated in the carburetor to supply the rich mixture necessary for starting cold engine
CHAPTER SIX
amount of airA typical idle mixture system is shown in Figure 4The pilot air screw controls small amount of air mixed with fuel from the pilot jetOpening the pilot air screw (sometimes called an idle mixture screw) permits more air to enter the idle mixture system and leans the mixtureAs the throttle is opened further, more air enters the engine around the throttle slide as shown in Figures and 6Fuel is drawn into the air stream through the needle jetThe jet needle limits the amount of fuel flowing through the needle jet