I have purchased a 1991 225hp Yamaha. The previous owner says that the yearly service has been done "professionally" and that he always pays extra for the synthetic gear lube. I asked him what brand and he said "Red Line". I am familiar with Red Line synthetic products, but is there a special lube for lower units?, is it a generic lube?, anybody have any idea what to use if I want to stay with Red Line? Engine has never had any repair to lower unit or power head, so he must be doing something right (500 hours). 
