Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 242Get this manual
SHIFT SPOOL ASSEMBLY COMPONENT REASSEMBLY 1Assemble the shift spool and shift spool shaft as follows:
SHIFT SPOOL ASSEMBLYADJUSTMENT Note: If the shift spool assembly has been disassembled and reassembled (as in the previous two sections) skip the following instructions, (1 through 4)Note: If the shift spool assembly has not been disassembled and reassembled do all of the following steps123Remove and discard the cotter pinScrew the castle nut down until it touches the washer and slight resistance is feltLoosen the castle nut until the cotter pin slot of the castle nut is aligned with the hole in the shaftIf, when the castle nut is screwed downthe cotler pin slot is aligned at the hole in the shaft, back off the castle nut until the next available slot in the nut is aligned with the hole in the shaftInsert new cotter pin and bend ends in opposite directionsInspect to insure that the spool spins freely (it may be helpful to lightly tap the forward [castfe nut) end of the shift spool shaft against firm surface to align the internal parts)Inspect to insure that the spool has 0.0020.0 10 in(0.050.25 mm) end play, if it doesn't, adjust the castle nut once again as outlined previouslyPlace the shift spool onlo the shift spool shaft