1971 Johnson 125HP outboards Service Manual, Page 26Get this manual
cInspect and clean casting contact area; if nicks, scratches, or an out-of-round condition exist, the casting will have to be replacedIf the casting opening is normal, apply bead of Sealer 1000 to the outer edge of new core plug and place the new core plug in the casting opening, convex side upFlatten to tight fit with flat end punch and hammerSee Figure 3-15LEAF VALVES aInspect the leaf plate assembly and disassemble if necessaryThe leaf valves must be free from all varnish and gum, and the leaves must be perfectly flat and without distortion so that they form seal with the leaf plate baseSee Figure 3-17bDO NOT attempt to bend or repair damaged leaf; replace the complete assembly if damaged00 NOT under any circumstances bend or flex the leaves by handcReplace the leaf plate assembly if any leaves or leaf "tops are damagedAUTOMATIC CHOKE For efficient operation, the solenoid plunger should be free from dirt and corrosion so that it can move freely in the housing00 NOT lubricate the plunger, since the oil film will only attract dust and cause sluggish plunger movementOperation of the thermal switch in the cylinder block can be checked with continuity light connected between the switch lead terminalsThe light should indicate closed circuit on cold motor and open as the motor reaches approximatley 100FFor replacement of thermal switch, see Section 5, Figure 5-13