Johnson Evinrude Outboard Motors 1956-1970 1.5-40hp repair manual., Page 63Get this manual
RODS critical during inspection if the engine has been submergedCarefully check each wrist pin to be sure it is not the least bit bentIf wrist pin is bent, the pin and piston MUST be replaced as set, because the pin will have damaged the boss when it was removedCheck the wrist pin bearingsIf the bearing is the pressed-in type, use your finger and determine the bearing is in good condition with no indication of binding or "rough" spotsIf the wrist pin bearing is the removable type, the needle should be replacedGrasp each end of the ring with either ring expander or your thumbnails, open the ring and remove it from the pistonMany times, the ring may be difficult to remove because it is "frozen" in the piston ring grooveIn such case, use screwdriver and pry the ring freeThe ring may break, but if it is difficult to remove, it MUST be replacedOBSERVE the pin in each ring groove of the pistonThe ends of the ring MUST straddle this pinThe pin prevents the ring from rotating while the engine is operatingThis fact is the direct opposite of fourcycle engine where the ring must rotateIn two-cycle engine, if the ring is permitted to rotate, at one point, the opening between the ring ends would align with either the intake or exhaust port in the cylinderAt