Yamaha 115-225 HP Outboards Service Manual, Page 246Get this manual
I 050005"
ROUGH IDLING
ROUGH IDLING
Replace the fuel
Are all wiring connections tight? YES
Tighten(P3-2-3-10)
Are the spark-plugs tightly screwed in?
Tighten(P3-41)
Does sparking take place in all cylinders?
Is the lighting coil used to supply heavy load? Are the ignition sequence and timing correct? YES Are the settings of the carburetor correct?