1976 Mercury 850 85 hp with power trim - won't go down

[siel67]

I am a total newbie on this site, and a newbie boat owner. I have a 1976 Starcraft Super Sport with the above mentioned outboard motor and power trim/tilt, that at the current time won't go down. We had this trouble a little while ago and my dad fiddled with the 'reverse lock operation' and it worked. We used the boat yesterday and the tilt worked, traveled for a bit and stopped at a beach, tilting the motor. Went to leave and the tilt wouldn't go down. It sounds like it is trying to engage but nothing happens. I honestly don't know where to begin. There is no 'screw" on the motor itself to disengage the tilt/trim. I can't find a name on the part (see picture), so I am at a loss at what to do. I would appreciate any and all help. Thank you!

 

[Chris1956]

Does the PTT motor run in the down direction? If not fix the wiring, or the PTT motor, or the solenoid (if it has a down solenoid, not all do).

If the PTT motor runs in the down direction, but the motor does not trim down, trim it up for a second and then down. Also, check the manual tilt lock (dog eared shaped pieces of steel on the transom bracket. They can get jammed.

To lower it manually, loosen one of the large hydraulic lines on the base of the pump/reservoir. Oil will shoot out, but the motor will tilt down, unless it is mechanically hung up.

 

[Chris1956]

Actually, you may need to loosen the smaller hydraulic hoses, to lower the PTT unit.

 

[siel67]

Actually, you may need to loosen the smaller hydraulic hoses, to lower the PTT unit.

Hi Chris1956

Thanks for your reply, I appreciate that. Can you tell me what the part in the picture is called? Is it the tilt/trim motor? It is in such an awkward placement. My dad is my boat mechanic, lol, so I’ll pass this info on to him.

 

[Chris1956]

That is a PTT motor/reservoir. They normally have a wrap around (from back) bracket, that can be screwed to the deck to hold it in place. You should strap it down.

The slotted screw in the top right of the unit is the fill. It should be topped off with either 5W30 motor oil or Dextron auto trans fluid. I would look at the color of the existing fluid and if brown use the motor oil. If red, use the ATF. Try not to mix 'em.

Just left of the fill screw, a bit higher is the vent that should be cracked open a small amount to let the reservoir breath.

 

[siel67]

That is a PTT motor/reservoir. They normally have a wrap around (from back) bracket, that can be screwed to the deck to hold it in place. You should strap it down.

The slotted screw in the top right of the unit is the fill. It should be topped off with either 5W30 motor oil or Dextron auto trans fluid. I would look at the color of the existing fluid and if brown use the motor oil. If red, use the ATF. Try not to mix 'em.

Just left of the fill screw, a bit higher is the vent that should be cracked open a small amount to let the reservoir breath.

Thanks very much Chris1956 for your help!

 

[racerone]

See the knob under the reservoir ?----What does that do ?.----Possibly a bad shift switch.----Try direct to the pump motor with some jumper wires.

 

[Chris1956]

The knurled knob under the reservoir is a reverse lock. If the motor is down, you can turn it CW and then lift the motor up by hand (with difficulty). If the motor is lifted hydraulically, and you release the reverse lock, nothing happens to the engine. It stays tilted.

 

[jimmbo]

The knurled knob under the reservoir is a reverse lock. If the motor is down, you can turn it CW and then lift the motor up by hand (with difficulty). If the motor is lifted hydraulically, and you release the reverse lock, nothing happens to the engine. It stays tilted.

That was how it was Designed. To lower the engine, you pretty much have to open the Hoses to the Rams. I suspect the Engineers figured if you had to raise the Motor by hand, there was something wrong and the Unit would need to be serviced. In the 70s the Oil Specified was SAE 20