1978 Johnson 175, 200, 235 HP Outboard Service Manual, Page 82Get this manual
gRemove the piston rings from pistons by prying ends loose enough to grip them with pliers and then breaking them away from the pistonInstall complete set of new rings on every power head service jobh If necessary to remove wrist pin, remove wrist pin retaining ring, using needle nose pliers See Figure 5-38 Figure 5-38 Removing Wrist Pin Retaining Ring
1"L" (loose) side
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Figure 5-40Pressing Out Piston Wrist Pin (Use Arbor Press)
One side of piston is marked "L" (loose) on inside See Figure 5-39When wrist pin is to be removed, "L" side of piston must be up and arbor pressing tool must be applied to loose sideAlways press from loose side to tight side, being careful not to distort pistonSee Figure 5-40 iDrive wrist pin through to free piston from rod
CLEANING, INSPECTION, AND REPA'R
CYLINDER BLOCK AND CRANKCASE Check cylinder walls for excessive wear, and check cylinder ports for carbon accumulationCylinder walls wear in various degrees depending on lubrication and conditions under which the motor is operat edMajor portion of wear is in the port area and the area covered by ring travelCheck cylinder for size and wall straightness by using an inside micrometer or dial bore in'd icatorRefer to Section for specified dimensionsIf wear is greater than .004" (0.10 mm), rebore block for oversize pistonsPistons and ring sets are availableSee Section 2, Specifications