Just bought this motor a couple of months ago used and have not changed the lower unit gear lube yet. Not sure if there is anything special about it. Bought a kit at Walmart, which says that I drain the oil from the lower plug and then pump the new oil back into the lower plug hole until the oil comes out of the upper vent oil. If this is correct does anybody know approximately how many quarts of oil I will need to fill the lower unit up. I am a new boat owner and not sure if this is correct this is probably really basic yearly maintenance but just want to make sure I am doing the right thing. Thanks for any help.