1978 Johnson 175, 200, 235 HP Outboard Service Manual, Page 83Get this manual
With continued operation of the motor, the cylinder walls will take on glaze which reduces the effectiveness of the seal between the piston rings and cylinder wallsThe result will be reduced compression and decrease in performance of the motorBefore reinstalling the pistons, break the glaze by using cylinder hone to refinish cylinder wallsUse low rpm on drill with rapid up and down movement to obtain good crosshatch pattern for good oil retentionUse hone with medium stone (220 grit)See Figure 5-41 63 49 6
Figure 5-42Surfacing Cylinder Head