1971-1973 Arctic Cat Snowmobiles Factory Service Manual, Page 98Get this manual
CARBURETION (TILLOTSON) 11The idle discharge ports and the high speed nozzle check valve are sealed from the metering chamber by two (2) welch plugsIt should not be necessary to remove these plugs because very Iittle wear is sustained in these areasIf dirt accumulates, it usually can be blown out through the high and low speed needle holes by using compressed airIf removal of the welch plug(s) is necessary, perform the following steps:shaftPull throttle shutter from between the split section of the throttle shaft
Using 18 inch bit, drill through the welch plugAllow the bit to just break the top surface of the welch plugCAUTION: Casting may be damaged if the bit is allowed to penetrate too deeply into the cavityUsing small punch, pry the welch plug out of its seat16Remove the throttle shaft retainer screw and washerSlide throttle clip off throttle shaftPull throttle shaft from main body of the carburetor1712Observe the idle discharge ports and insure there is no evidence of obstructionRemove obstruction, using compressed airCAUTION: Do not remove an obstruction by using bits, nails, or wires; damage to the carburetor may result in poor performance if such items are usedRemove the high speed nozzle ball check valve assembly with screwdriver of correct widthFor most service applications, the carburetor need not be further disassembledIf the choke or throttle shutters show signs of wear or are malfunctioning, replacement of these components must be madeIf replacement is necessary, continue using the following steps: Remove the two (2) throttle shutter screws and washers securing the throttle shutters to the throttle