1978 Johnson 55 HP Outboards Service Manual, Page 69Get this manual
REASSEMBLY OF POWER HEAD Proceed slowlyMake no forced assemblies unless press fits are called for and make no "dry" assembliesBe sure all parts to be assembled are clean and free from dirt and gritPerfectly good cylinder wallS, pistons and rings can be ruined in few minutes of operation unless all forms of grit are removed before assemblyWork in clean surroundings and with reasonably clean handsCoat all bearing surfaces, cylinder wallS, etc with clean oil before assemblyWhere the use of "oil" is specified, we recommend OMC Outboard LubricantNOTE Always use new gaskets and seals throughout when reassembling the power headMake certain all oil holes and passages are openPISTONS, WRIST PINS AND CONNECTING RODS
cReplace retaining rings, making certain they come to rest securely in the groove provided for this purpose, using OMC Special Tools Cone Part #318600 and Driver #318599See Figure 5-32A
PISTON RINGS BACKED RING)
RING IS PRESSURE
Install the piston rings on each pistonSpread each ring with ring expander just enough to slip it over the head of the piston and down into placeBe sure the rings fit freely in the piston ring groovesThe ring grooves are pinned to secure the position of the rings, primarily to prevent ends of the rings from catching on the edges of the ports in the cylinders but also to assure staggering of the ring gaps