Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 367Get this manual
4Inspect to insure that the spool spins freely (it may be helpful to lightly tap the forward [castle nut] end of the shift shaft against firm surface to align the internal parts)5Inspect to insure that both ratcheting and nonratcheting spools have 0.002-0.010 in(0.05-0.25 mm) end playThis end play may be achieved by turning the castle nut (clockwise) down on either spool until it is snug and then backing off the nut (counterclockwise) to the first cotter pin slot NOTE: If the spool meets the above two criteria skip the disassembly and reassembly section followingNOTE: If the spool does not meet the above criteria proceed with the disassembly and reassembly section followingSHIFT SPOOL ASSEMBLYComponent Disassembly NOTE: Disassembly of the shift spool is for cleaning and inspection of the internal parts due to an improperly functioning shift spool assembly or debris in the gear housing andor shift spool assemblyIndividual components for the shift spool are not available as replacement partsIf the shift spool does not function properly (see the preceding "Shift Spool Assembly Inspection" section) and the following cleaning and adjustment procedures do not produce the desired results, it will be necessary to order new shift spool assembly+.002 (0.05mm) to .010 (0.25mm)