1981 Johnson/Evinrude 4HP Outboards Service Manual, Page 26Get this manual
bIf leakage persists, drill 18 inch (3.2 mm) hole through the center of the core plug to depth of not more than 116 inch (2 mm) below its surfaceWith punch, carefully pry out the core plugSee Figure 3-14cInspect and clean the casting contact areaIf nicks, scratchesor an out-ot-round condition exist, the casting will have to be replacedIf casting opening is normalapply bead of OMC AdhesiveMil to the outer edge of new core plug Place new core plug in casting, convex side up Flatten to tight fit with flat end punch and mallet, and check for leakageLEAD SHOTS If leakage occurs at lead shot area, follow these corrective measures: aIf leakage is slight, smart tap with hammer in the center of the lead shot will normally correct this conditionSee Figure 3-15Figure 3-16Removing Lead Shot 81 93
FUEL TANK aInspect the filler cap and gasket for wear, damage, or leakage; replace if necessarybRemove shut-off valveRemove gum and varnish deposits by washing in OMC Engine Cleaner (OMC Engine Tuner)Apply drop of OMC part number 200763 Gasoila to threads at shut-off valve on installation to fuel tank cInspect the fuel tank for leakageIf leakage occurs, replace tank dFlush tank with clear gasoline or solvent at least once year