1991 Yamaha Outboard Factory Service Manual 9.9 and 15 HP, Page 14Get this manual
The propeller size is indicated on the back of the blade9-14 12J L-._ _
Propeller type
Propeller pitch
Propeller diameter
the right propeller for the boat is one which gives maximum performance in relation to boat speed and fuel consumptionThe propeller mounted on outboard motors at the Yamaha factory is designed for standard operating conditionsTherefore, it cannot meet the operating conditions of every boatI other words, the right propeller must be selected according to the type, displacement and load of the boat
Dual thrust propeller