OMC Stern Drives And Motors 1964-1986 Repair Manual., Page 7Get this manual
A zinc plate attached the bottom side of the intermediate housing
The propeller washer is installed on the hub prior to inserting the drive pin through the propeller mc? shcftThe propeller, washer, nut, and drive pin should be checked regularly for cracks and wear
Using Zinc The proper amount of zinc attached boat is extremely importantThe use of too much zinc can cause wood burning by placing the metals close together and they become "hot"On the other hand, using too small zinc plate will cause rapid deterioration of the the metal you trying protectIf in doubt, consider the is better replace the zincs than replace planking other expensive metal parts from having an excess of zinc
When installing zinc plates, the two routes availableOne is install many different zincs on all metal and thus run the risk of wood burningAnother route, is use one large zinc on the transom of the boat and then connect this zinc every underwater metal part through internal bondingTwo types of zincs may purchased from the local OMC dealerO bolts the boat transom with wire connected to the batteryThe other type is bolted the bottom side of the intermediate housingIn later years, OMC stern drive units sold with the zinc attached the intermediate housing standard factory equipment1-4 PROPELLERS