1992 Johnson Evinrude "EN" 40 thru 55 Service Manual, P/N 508143, Page 317Get this manual
it General Safety Warnings Before working on any part of the hydraulic system, read the section called Safety at the end of this manualBefore returning motor to owner, verify that manual release valve is torquedReplace any locking fastener (locknut or patch screw) if its locking feature becomes weakDefinite resistance to tightening must be felt when reusing locking fastenerIf replacement is indicated, use only authorized replacement or equivalentWhen servicing this hydraulic unit, only use the service procedures outlined and the correct parts catalog for this specific unitSome internal components may appear similar to those in other hydraulic units but may have different operating pressures and characteristicsInterchanging these components may have an adverse effect on the unit's operationBe sure the thrust rod is correctly adjustedThis will prevent the possibility of loss of boat control should the motor trim "in" too far