1998 Johnson Evinrude "EC" 9.9 thru 30 HP 2-Cylinder Outboards Service Manual, Page 281Get this manual
Battery Cable Extension The following are MINIMUM specifications for stranded copper cable without splicesCable measurements given are from the motor to the batteryThe maximum length is 20 feet, regardless of cable diameter
INote These specifications do not apply to aluminum battery cablesOMC does not recommend the