2009 Yamaha F40 Outboard Service Manual, Page 130Get this manual
Electrical system Brush holder assembly continuity: d
Commutator standard undercut b: 0.5 mm (0.02 in) Wear limit: 0.2 mm (0.01 in) 4Check the armature for continuityReplace if out of specification
2Measure the length of each brushReplace the brush assembly if below specification
Brush standard length f: 12.3 mm (0.48 in) Wear limit g: 5.5 mm (0.22 in)