Yamaha 115-225 HP Outboards Service Manual, Page 181Get this manual
2) Check the wire for looseness, flaws, fluffy or any other damage, and check both end balls for insufficient grasp of wireReplace the wire assembly if any such defect is found 3) Clean the cowling release lever and check for any critical damage
4) Tighten the shaft securing nut to torque specificationShaft securing nut: 8.0 Nm (0.8 m.kg, 5.8 ft.lb)
Insufficient driving torque may cause the shaft securing nut to come off and then the shaft to dropIf the shaft drops, the cowling release lever is not able to actuate both front and rear cowling locks to release the top cowling