BARR MC-1-99798 DIRECT REPLACEMENT FOR MERCRUISER 4-cyl engines 1983 to 1995 using 2-bbl MERCARB with electric choke. (Carburetor has a single idle air adjustment screw with a bolt pattern of 3-11/16" x 2"). 6-bolt mounting pattern to head. Direct replacement for Mercuiser part 99798A3, 99798A9, 99798A16 and 860235A04. Riser mounting flange with square bolt pattern (2-13/16" x 3-1/16" bolt centers), Made by BARR in USA, 3-year limited warranty.