1991 Yamaha Outboard Factory Service Manual 9.9 and 15 HP, Page 135Get this manual
STARTER MOTOR DOES NOT TURN OVER
ELECTRIC
Fuse Burnt out Battery Is the battery fully charged? Wire harness connector Faulty Neutral safety switch Faulty Main switch Faulty Starter relay Fau Ity Starter motor Overrunning clutch or damaged pinion Carbon brushes are worn Carbon brush springs are fatigued Commutator is worn Armature coil or field coil is broken or shorted Armature shaft bushing is worn, Lacks oil