Yamaha 115-225 HP Outboards Service Manual, Page 241Get this manual
ENGINE WILL NOT START If the relay chatters, turn off the power immediately to prevent damage to the relayCharge the
battery completely and re-check the relayIf it still chatters, either the battery or the starter motor may be faultyCheck
Does the terminal on the secondary side (connected to starter-motor) conduct? -U-YES Check the starter-motor(P8-388-40) Is any trouble found?
, Replace the starter-relay(P8-28)
Repair(P8-38-8-40)
RE-CHECK
Is either the starter-pinion or the flywheel gear broken?
Replace(P8-38)
Is there enough fuel in the tank? OYES
Add fuel