1991 Yamaha Outboard Factory Service Manual 9.9 and 15 HP, Page 26Get this manual
WARNING: Battery electrolyte is poisonous and dangerous, causing severe burns, etcIt contains sulfuric acidAvoid contact with skin, eyes, or clothingAntidote: EXTERNALFlush with waterINTERNAL Drink large quantities of water or milkFollow with milk of magnesia, beaten egg, or vegetable oilCall physician immediatelyEyes: Flush with water for 15 minutes and get prompt medical attentionBatteries produce explosive gasesKeep sparks, flame, cigarettes, etcawayVentilate when charging or using in closed spaceAlways shield eyes when working near batteriesKEEP OUT OF REACH OF CHILDREN
TEST PROPELLER Whenever the motor is tested, (for instance, before it is delivered to the customer of after overhauled) be sure to use test tank and test propellerI the originally mounted propeller is used, the test tank may overflow or the water level may fluctuate sharply, thus causing cavitation with marked increase in rpm or propeller slipTherefore, it is impossible to check if the motor has been correctly overhau ledThe test propeller is designed to turn stably even in the test tankIf the tachometer readings are within the specified speed range when the motor is run with the test propeller, the motor is considered to be properly servicedIf the engine speed is far below the specified speed, the motor will have to be checked againSpecified motor speed: 9.9N 5,0005,200 rmin 15N 5,2005,400 rmin