Yamaha F100B F100C Outboards Factory Service Manual, Page 252Get this manual
Bracket unit
4Check the armature coil for continuityReplace if out of specifications
Checking the power trim and tilt motor
1Check the commutator for dirt or foreign substancesClean with #600 grit sandpaper if necessary
2Check the commutator undercut for dirt or foreign substancesClean with compressed air if necessary3Measure the commutator diameter aReplace if out of specificationArmature coil continuity Commutator segments Segment-laminations Segment-shaft Continuity No continuity No continuity