This Sierra International 18-70940 is a replacement needle and seat assembly for certain Mercury Marine inboard engines. It's a crucial carburetor component that controls fuel flow into the float bowl. Fits many MCM V6 and V8 engines including 305, 350, and 377 cid models. Specifically compatible with: 262Mag with fuel cooler, 4.3L-LX (1996 and up) with one-piece manifold, 5.0L-EFI (1998 and up), 350Mag-MPI (1997-2001), 5.7L-EFI (1996-1997), and 6.2L MPI (2001 and up). Always double-check your engine's exact model and year, and compare with the original part to ensure proper fit. A genuine Sierra part known for reliability in marine applications.
