06-09-2017 06:59 - edited 06-09-2017 07:00
That is a modified standard gearcase that has an add-on nosecone welded or bonded on. They then drill and tap for fittings and a water hose on the side of the gearcase.
It is not real common for a 115 HP unit, as nosecones are more often used for high speed V-6 rigs where the 'cone can allow the motor to run at a higher transom level and the extra length helps prevent blow-out over the OEM gearcase shape.
"There is never just one thing wrong with a boat";
-- Travis McGee, main character in a book series by John D. McDonald
The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.
The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.