1995 Johnson/Evinrude Outboards 9.9, 15 four-stroke Service Manual, Page 29Get this manual
Preseason Service 1Check gearcase lubricationIf leakage is evident, gearcase seals may need attentionSee Lubrication, this section
2Apply light coating of OMC Triple-Guard grease to the ribbed portion of the spark plug ceramics and the opening of the spark plug coversConnect spark plug leadsMake sure spark plug boots are not cracked or torn
3Check water level in battery, then chargeWhile the battery is charging, the acid solution inside the battery gives off hydrogen gas which can explode if ignited by spark or open flameIf hydrogen gas is not able to leave the battery (vents are clogged), the battery itself may explodeTherefore, when charging batteries, make sure that battery is vented to atmosphere and lots of fresh air is in the areaMake sure no sparks or flames are presentDo not short across battery terminals to check battery conditionInstall and connect battery