1990 Mercury Black Max 175 2 stroke carb - trim pump is dead - need advice before proceeding

[OldGuy77]

Tilt and trim went out intermittently appeared to be electrical - then it quit on me while fishing luckily engine was in mid standard tilt position - powered back to my slip - tilt then worked fine. Next day tilt and trim worked fine on run out but when stopped to fish - no tilt - powered back to slip - tilt still dead - cowl, bow and remote. Checked all electrical including fuses all fine. Solenoids would click loudly when engaged telling me tilt motor was getting power. Didn't trust the solenoids so tore it down and got to the 3 wires from the motor - blue, green and black. Took jumper cables from battery 12.9 to black wire and blue wire nothing. Tried green wire nothing - checked connecting end of jumper cables 12.9. Determined tilt motor is bad. When researching new tilt motor determined per my ser# that have the old school Design 1 system - 3 wires vice 2. Now for some advice was able to get boat on trailer and back into dry storage without having to raise the motor (done very carefully). In attempting to release the manual tilt valve the plastic screw head broke - well it's 33 years old lol. Not sure I need a new one. But the question becomes can I release/disconnect the motor from the power tilt system? Just looking at it appears I can but not sure so asking. New plastic valve assembly is $68 and not how to get the old one out without creating new problems. Have seen the videos of the problems pertaining to the back screw on the tilt motor so any suggestions on dealing with that issue are appreciated. I just thought if I take the necessary bolts out and the nuts securing the plungers I should be able to raise the foot and anchor then reconnect everything once the new motor is installed or am I just dreaming? Sure some have you out there have dealt with similar issues so reaching out for help and dialogue. Secondly planning on going to a two wire system with relays - it's the newer design so think it would be better?

 

[OldGuy77]

Update - after further research found a thread on the hull truth whereby 1 - don't try an easy out you will regret it 2 - take flat head torch it and then push it into the plastic head forcing a new slot - let cool and then try to use the screw driver to release it with the new slot?? Comments success or misery stories??

 

[Chris1956]

The trim pump motor can be removed from the engine, after removing the PTT bolts and starboard side transom bracket. Usually it takes an Allen wrench to loosen the screws holding the PTT motor. The outboard motor can be trimmed down for this.

Alternatively, you can remove the six bolts that hold the PTT unit to the transom bracket, and partially lift the engine, gaining access to the tri lobe pin. If you drive out the tri lobe pin, and then the PTT pin, the motor will tilt manually.

The replacement can be a 3 wire or a 2 wire motor. Make sure any 2 wire motor that you buy comes with a wiring harness and the 2 relays necessary for that motor style. ARCO and Sierra make replacement motors, at a minimum.

 

[OldGuy77]

Thanks for such well written directions. The two wire I liked was the Arco have a starter from them that works well. And the Arco comes with the relays and wiring. Thanks again. I had read my service manual and had some idea what to do but your experienced reply really helped see how and what needs doing and an alternative. Thanks again.