Trim Motor OMC 172588 173944

Function and Technical Context

The trim motor is the electrohydraulic component responsible for regulating the tilt angle of the outboard motor relative to the transom, allowing the pilot to adjust the propulsor position to optimize navigation performance. It operates within the outboard trim and tilt system, converting the electrical signal from the helm trim buttons into hydraulic movement that raises or lowers the motor's stern. A failure in this assembly prevents angle of thrust adjustment, resulting in loss of fuel efficiency, difficulty in reaching planing speed and risk of mechanical damage by being unable to retract the motor from the water in shallow depths or during transport. OMC references 172588 and 173944 correspond to the motor-pump assembly of the trim system, specifically designed for small-displacement outboard engines from Johnson and Evinrude brands.

When to Replace This Part?

The most common symptoms of a defective trim motor are slowness or complete lack of response when operating the trim buttons, spontaneous motor descent after setting the position or the appearance of abnormal noises (buzzing or clicking) during movement. It is recommended to inspect the assembly at each seasonal maintenance, checking the hydraulic fluid level, the condition of electrical contacts and the cylinder seal integrity. Replace the trim motor at the first signs of failure to avoid being stranded at the dock or suffering damage to the power unit due to incorrect trim positioning during navigation.

Compatible Johnson/Evinrude Engines

Equivalent Manufacturer References