1991 Yamaha Outboard Factory Service Manual 9.9 and 15 HP, Page 112Get this manual
NOTE: 1The length of each bolt is shown on the bracketUse care so that the bolt position is correct2One of the four bolts is also used to fasten the battery wire CHARGING SYSTEM INSPECTION
Lighting coil Refer to page 6-2Rectifier Check resistance and continuity using the Yamaha Pocket Tester (1 scale)
Never connect the rectifier directly to the battery to check continuity2When testing, disconnect the battery terminals3When resistance is measured at less than 1oon, it can be said that there is continuityRectifier resistance test 1Check the rectifier as specified using the pocket tester2If any element is broken, replace the entire unit1Fasten the positive wires coming from both the starter motor and the battery to the starter switch with the screws, and connect the positive wire of the battery to the fuse lead