2007-2009 Yamaha F15/F20 Outboard Service Manual, Page 272Get this manual
Troubleshooting the power unit Symptom 1: Power tilt unit does not hold the outboard motor up Symptom Cause Manual valve left open Insufficient power tilt fluid Power tilt fluid leakage Clogged fluid passages Malfunction of the power tilt unit internal parts Cause Manual valve malfunction Checking step Check the manual valveAdd sufficient fluidCheck the power tilt unit for leakageDisassemble and check the power tilt unitRefer to page 7-38 3-13 7-43 7-38