Honda BF20A-BF25A, BF25D-BF30D Outboard Motors Shop Manual., Page 286Get this manual
No.2 Carburetor Gasoline is highly flammable and explosiveYou can be burned or seriously injured when handling fuelKeep heat, sparks, and flame awayHandle fuel only outdoorsWipe up spills immediately8 Before disassembly, completely drain the carburetor by loosening the drain screwClean the outside of the carburetor before disassemblyI WASHER SCREW (4)
Blow each passage with air before assemblyDo not reuse the O-ringsReplace them with new ones on assembly[lo] O-RING
1 Do not reuse[17] DRAIN SCREW