Trim issues

[Mrobi]

Hello all
I am having problems with trimming my lower unit. Goes down fine but comes up halfway slowly then needs help the rest of the way. And stays up. I have no leaks that I can see and the reservoir is full. I'm assuming it's my pump but before I splurge for a new one I'd like to be sure. Any suggestions?

 

[Chris1956]

Can you give us a hint on what motor? There are quite a lot of different PTT units on different year Outboards and Sterndrives.

 

[Mrobi]

I have 1991 Larson 18 Lazer se with the 3.7 liter.

 

[Chris1956]

MerCruiser? Alpha 1 Gen I?

 

[Mrobi]

Mercruiser alpha1 gen 1. I believe.

 

[Mrobi]

I also so have a prop question. Should I start a new thread for that?

 

[Chris1956]

That PTT system probably has 1 solenoid for "Up" and another for "Down". Does your trailer button work to trim motor up faster? If so, the trim limit switch on the outdrive is likely bad.

If not, for slow trim up, check the wiring from the battery to the "up" trim solenoid. They are wired very much like a starter solenoid, with a heavy cable to the solenoid secondary winding and lighter wiring to the solenoid primary.

 

[Mrobi]

When we bought the boat late last year The trailer switch was disconnected. And I'm pretty sure the limit up switch is not functional. The wiring from the pump(blue, green and black) to the solenoid seems to be fine. Will the nonfunctional limit up switch prevent the pump from Appling enough hydraulic pressure to raise the lower unit effectively?

 

[Chris1956]

No, if the trim limit switch was disconnected, it would prevent the pump from running.

Jumper from the battery to the up solenoid (blue pump wire), primary (small) terminal. If she trims up at normal speed, the issue is in the wiring, or switch on the control.

Make sure the black wire from the PTT motor is clean and connected to ground (negative battery terminal).

Other than that, you will need to get a wiring diagram and trace out the circuit.


I

 

[Mrobi]

So if it trims up slowly and not fully is it safe to say it's probably a pump issue?

 

[Bob_VT]

Once it is trimmed up and stops........ release the up switch and try it again. Sometimes that is the only way to get an outdrive into the trailer position.

 

[Mrobi]

I have tried that and also tried raising it as far as it will go(which is about half way) then lowering it just a bit and raising it again. Sometimes it won't get back to halfway after trying this. Then I have to lift it manually will some presses the trim switch.
Thanks for everyone's help

 

[Chris1956]

Slow trimming could be a motor issue, solenoid issue or wiring issue. I lean towards a wiring issue. Why not trim the motor up as best as you can. Now switch the motor wires on the solenoid secondary posts. Now push the trim switch to trim it up, and the trim should run down, since the wires were switched. See if it runs down at slow speed or not. Slow speed means wiring or solenoid issue, not motor issue.

I once had a battery cable that had rotted out under the insulation. It looked fine and ohmed fine. When you tried to start the motor, the starter ran fast for a second or two than rapidly slowed. Within a few seconds, it struggled to spin the motor.

 

[Mrobi]

That kinda makes sense. The switch did seem to operate opposite of my previous 4 boats (up was down and down was up) Which I kinda thought in my head last year after I bought it. But I figured it was my old age catching up with me. I watched the seller lower it when we bought it but never seen them raise it. Where is the best place to bleed the hydraulic lines.
Thanks I'll put the motor back on and try that.

 

[Chris1956]

Alpha 1 PTT units are self bleeding. Just make sure they are full of fluid. Normally a Dextron II ATF is used.

 

[Mrobi]

Great news.. thanks

 

[Bradley532]

Hello all
I am having problems with trimming my lower unit. Goes down fine but comes up halfway slowly then needs help the rest of the way. And stays up. I have no leaks that I can see and the reservoir is full. I'm assuming it's my pump but before I splurge for a new one I'd like to be sure. Any suggestions?

you just remove the hydraulic fluid fill screw near the top of the trim reservoir and add fluid until it starts to overflow. Then trim the motor up and down, try to add a little more fluid and trim it up and down again. Do this several times to bleed all the air out of the system, and then put the hydraulic fluid fill screw back in, wipe off the excess fluid and your power tilt and trim may be work.

 

[Mrobi]

Thank you

 

[Grub54891]

The trim fluid will turn pink colors if there is air in it. You may have to check and fill after sitting for the air to settle out. When there is no mire air the oil will stay clear.

 

[Chris1956]

The ATF fluid will also turn pink when water gets into it. Of course the boat needs to be in the water for that to happen.