How to Service Power Tilt and Trim on Johnson Outboard Motors

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The power trim and tilt system used on Johnson outboard motors serves two purposes. The first is to trim your boat to optimize the laminar flow between the hull and the water -- it gets up on plane faster and rides better. The second function, tilt, allows you to raise your motor for beaching, trailering or docking in salt water, when you want to prevent the accumulation of salt deposits in the raw water cooling system.

Items you will need

  • Digital multimeter

  • Hydraulic fluid

Connect the multimeter black lead to a good engine ground and check for voltage at the battery side of the starter solenoid with the red multimeter lead. Mark the "Up" and "Down" relays and remove them from the relay sockets. Connect the red multimeter lead to terminal V1 and the black lead to V2 to check the "Up" circuit.

Push the tilt/trim "Up" button and check for voltage at terminal V3. Disconnect the blue/white tilt limit switch bullet connectors. Reconnect them, bypassing the tilt limit switch and repeat the previous step to test for voltage at V3 when pressing the trim/tilt up button on the lower motor cover. If voltage is present, replace the tilt limit switch.

Connect the red multimeter lead to relay blade M for terminal V4 and the black lead to a good engine ground. Disconnect the blue and green wire connector from the trim motor. Check for voltage on the blue wire when the Up" button is pressed. Repeat the same test for the "Down" circuit, using terminal V7.

Connect the red multimeter lead to terminal V5 and the black lead to V6. If the multimeter doesn't show 12 volts DC, check the red wire between the relay socket, the starter solenoid and the ground.

Push the trim/tilt "Down" button on the lower motor cover and check for voltage at V7. Press the "Down" trim button and watch for voltage on the blade at V7.

Remove the hydraulic reservoir cap. Add hydraulic oil to the reservoir until the oil is at the base of the reservoir's filler neck.

Run the tilt/trim system all the way up and all the way down at least five times. Add fluid and repeat, if necessary. Recap the hydraulic reservoir and lower the tilt/trim.


  • "Johnson Repair Manual -- 2.5 to 250 HP Models, 2002-2007"; Seloc Marine; 2007

About the Author

Will Charpentier is a writer who specializes in boating and maritime subjects. A retired ship captain, Charpentier holds a doctorate in applied ocean science and engineering. He is also a certified marine technician and the author of a popular text on writing local history.

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