78 evinrude 100 hp tilt trim problems

smallies4evr

Cadet
Joined
Feb 17, 2011
Messages
8
Went fishing yesterday. Lifted the motor to remove transom saver, launched boat, lowered motor and got underway. Motor would not continue down to the position to trim the boat to plane. Motor will not lift or lower now. Checked all connections, cleaned with wire brush, reconnect all wiring. I checked the solenoid with multimeter and I have voltage everywhere I should according to my manual. I have 12 volts at the wires going to the tilt/trim motor, however motor doesn't run. My engine is in a 3/4 down lowered position. What do I need to do to get it up to test the tilt/trim motor? I see in my manual that there is a check valve, etc but I can't get to them with my engine in its current position.
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: 78 evinrude 100 hp tilt trim problems

I assume you're having an electrical problem, not a hydraulic problem. If so........

Disconnect the electric motor at its connection. Run small jumper cables directly from a good fully charged battery to those wires of that electric motor. If the motor doesn't run, thern obvoiously it is faulty. Let us know what you find.
 

smallies4evr

Cadet
Joined
Feb 17, 2011
Messages
8
Re: 78 evinrude 100 hp tilt trim problems

Thanks for your advice. That is what I did and I found that I will have to pull the engine to get access to the pump motor. I tried removing all the tilt/trim mounting bolts to remove the motor but I can't get to the back screw on the pump. I guess I now have a winter project to do along with many other things on the boat that need some TLC.
 

Will Bark

Lieutenant
Joined
Aug 1, 2010
Messages
1,470
Re: 78 evinrude 100 hp tilt trim problems

The manual release/check valve is located in a hole on the starboard transom bracket, use a flat blade screwdriver and back 1&1/2 turns to release pressure and lift engine. Use your tilt lock to hold engine up or a peice of 2X4. I would think you can replace the motor without having to pull the engine if you have all four bolts out then you need to drive the tilt ram pin out and then the unit should come out. If your unit is different someone else will have to chime in. Good luck.
 
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