1983 Yamaha 30EN Outboards Service Manual, Page 128Get this manual
3 Check continuity between the insulated brush holder and groundIf there is continuity, the brush holder is grounded and should be replaced
Starter pinion gear Check for pinion wear or damageCheck also ease of pinion movement (sliding motion)
Note the following: 1After making sure the engine is ready to start, turn the starting switch to ON2If starting is hard, turn off the switch and turn it on again after 10 secondsRepeat this operation until the engine starts3Avoid turning the starter motor longer than requiredNever attempt to turn on the starter motor while the engine is runningReassembly Apply thin coat of anti-freeze grease (Yamaha all-purpose grease, PIN LU8-GREAS-13-00) to the rear cover bushing, and install the armature on the rear cover assembly