1983 Yamaha 30EN Outboards Service Manual, Page 113Get this manual
4Forward gear aShift into forward gear by pulling the sh ift rod upwardbLock the propeller shaft, and gently turn the drive shaft in and out while pushing it downwardWhen click is felt, stop turning and read the maximum deflection of the needleNOTE:
1Lock the propeller shaft tightly2Do not turn the drive shaft quickly, or the accurate measurement of gear backlash will be impossible3Take note of the dial gauge readings
Tightening torque: 90 Nm (9 m' kg, 65 ftlb) 3Install the dial gauge on the dial gauge stand and install it on the gear caseInstall the backlash indicator rod on the drive shaft and bring the dial gauge stem into contact with the "30A" on the indicator rod