1979 Evinrude 4 HP Outboards Service Manual, PN 5424, Page 57Get this manual
kIf necessary to remove pistons from connecting rod, remove wrist pin retaining rings, using needle-nose pliers See Figure 5-9Drive wrist pin through to free piston from connecting rod See Figure 5- 10 U NOTE lliilrU
One side of piston is marked "Lon insideWhen wrist pin is to be re moved, "Lside of piston must be down and driving tool must be applied to tight endBe careful not to distort pistonSee Figu re 5- 11
Figure 5-11"L" Mark on Piston
CLEANING, INSPECTION, AND REPAIR
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 operated Major 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 indicatorRefer to Section for specified dimensionsIf wear is greater than 0.002" (0.05 mm)replace cylinder block or rebore block for oversize pistonsPiston and ring sets are available 0.030" (0.76 mm) oversize