04-08-2013 11:00 - edited 04-08-2013 11:02
If the trim motor is running and the unit if full of oil, then there is a lack of hydraulic pressure that could be caused by a stuck-open valve, bad valve body, piston seal, or the emergency release screw is not fully screwed in and seated. Once in a very great while, the connector piece between the trim motor and the oil pump is found to be broken or missing.
Most of the time an internal trim unit repair requires a trained tech depending on make, model, and year.
"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.