2007-2009 Yamaha F15/F20 Outboard Service Manual, Page 214Get this manual
Power tilt motor (power tilt model) NOTE: Push the brushes apart, and then remove the armature assembly Do not remove the bearing from the armature assembly7Remove the brush holder screws C, brushes D, springs E, and oil seal from the power tilt motor base 0Motor commutator standard diameter: 16.5 mm (0.65 in) Wear limit: 15.5 mm (0.61 in) 3Measure the commutator undercut aReplace the armature if below specification C E
S6AG7125
Checking the power tilt motor
1Check the commutatorClean with 600grit sandpaper and compressed air if dirty