Honda GB40 Outboard Motor Manual., Page 32Get this manual
GDescription of bottom case The bottom case is the lowest portion of the outboard equipment and is streamlined for propelling eficiencyThe top section provides the propeller with an anti-cavitation plate for preventing possible cavitation during cruisingThe splash plate located on the cavitation plate is for preventing water splash caused during high speed cruisingThe interior serves as lubricant oil pool and is used lubricate the chain and bearing (etc(Fig73)
HDisassembly I.Tools necessary for disassembling and reassembling the bottom case are shown in Fig74