The Tillotson High/Low-Speed Mixture Screw Washer fits between your fuel adjustment needle spring and O-Ring.
The washer prevents the spring from crushing and tearing the O-Ring that seals the needle and the fuel high or low fuel circuit.
This particular brass washer fits the High and Low Adjustable Mixture Screw on most Tillotson Carburetors including HL, HB, HX, HM, HW but does not fit the high side needle of the HR Model Carburetors. Always check your carburetor listing before ordering.
78A-256 OE Tillotson Brass High/Low Mixture Screw Washer fits HL-1A HL-129E,HL-132H,HL-166B&C,HL-189F,HL-227A,E,HL-229A,HL-321E,HL-232A,E, HL-250A,B,C,D,E HL-274E, HL-,292G,HL-293A,F,HL-299E,HL-304E, HL-304WX,WXA,WXG,HL-306A, HL-314E,HL-314F&G, HL-324A,HL-334A,AA,B,AB,WX,WXA,WXG,HL-339A,HL-341A,HL-342A, HL-348A,B,C,D,E, HL-352A,HL-355A,B,C,D,E HL-357A,B, HL-360A, HL-360B,C HL-365A&B,HL-366A,HL-368A,HL-371A,HL-374A, HL-380A,B, HL-383A, HL-384A&B, HL-385A, HL-388A,HL-395A,HR-181B,HR-184A,HR190A,HR-191C,HR-191G,HR-196A,HW-10A,B HW-11A,B, HW-12A, HW-17A, HW-19A, HW-22A, HW-23A, HW-27A, HW-30A, HW-31A, HW-32A, HW-33A, HW-34A, HW-35A, HW-43A, HB-10A, HB-11A, HB-12A, HC-103A,HC-112A, HM-1A, HM-2A, HM-12A, HX-10A, HX-12A