Chrysler 100, 115 and 140 HP Outboard Motors Service Manual, OB 3439, Page 138Get this manual
DMeasure crankshaft 9Check connecting rod as follows: AMeasure both ends of connecting rods with inside micrometer NOTE
If gap is too tightit can be opened with file ReassemblyPower Head GENERAL NOTES:
Assemble caps on rods, torque to specifications to establish proper diameter10Check pistons as follows:
AClosely inspect pistons for wear and scoring
1Internal parts have close tolerance, so it is most important that all partsthe work areaand your hands are clean 2With new or rehoned cylinders, the bores should be thoroughly scrubbed with warm soapy water using round pore brush Dry thoroughly 3Follow torque valves closely when tightening screws Threads in aluminum castings are often damaged by over tightening 4When heat is called for in assembling press fit partsheat gun is advised Open flame destroys protective coatings and paint 5Coat cylinder walls with oil6Use only specified gaskets InstallationPiston Assembly
The type of damage helps determine the cause: diagonal wear is not normalnew pistons can be damaged quickly in the same wayScoring can be caused by overheating, incorrect ignition timingincorrect clearances between piston and cylinder andor improper break-in procedure BMeasure piston at right angle to piston pinCheck for wear at top land and skirtC Measure piston micrometer pin bore with an inside