Power trim

[thumper48]

Help I have 1979 evinrude 85 hp motor will go up but will not go down. Anyone able to help.

 

[ezeke]

Re: Power trim

The 79 trim motor has three wires, blue green and black. The black wire is a common ground. The green wire lowers the unit when positive voltage is applied. The blue wire raises the motor when positive voltage is applied.

The switch applies voltage directly to the trim motor when lowering the motor. The switch activates a single solenoid for raising the motor.

If the problem is electrical, It will be limited to the wires colored green in the diagram.

 

[thumper48]

Re: Power trim

trim motor runs in down mode will not lower out board. Is there a manal for trim unit .can it be rebuilt

 

[ezeke]

Re: Power trim

There's a fairly lengthy section on the PT&T in your factory service manual: http://www.outboardbooks.com/index.cfm?fuseaction=search.main

In the meantime read this about same unit on a different motor: http://forums.iboats.com/showpost.php?p=2185325&postcount=2

 

[RRitt]

Re: Power trim

trim motor runs in down mode will not lower out board. Is there a manual for trim unit .can it be rebuilt

there should be a fitting with flathead screwdriver slot. It should be labeled manual release. If you get a large enough screwdriver to turn it without damaging the slot does your engine let down? If you have rams up under your engine the turn it 1/4 turn. If your rams are outside transom clamps then turn it 3-4 turns ccw.

If the motor falls with manual release open then your hydraulic rams are probably okay.
If the rams are okay and you can hear the trim motor running ... but it still doesn't go down then it is probably a problem with valve body. I don't know if anybody even has these parts anymore. Maybe you can find some NOS on ebay?

 

[thumper48]

Re: Power trim

On the advise from a friend in Alabama, I loosened the hydraulic line from the bottom of the tilt cylinder, removed the screw from the hydraulic reservoir, bled the line and let the motor come down to the trim cylinders. I then refilled the reservoirs with marble mystery oil, raised the motor up slightly and allowed to set. Every 2 hours, I would try to lower & raise the motor. After about 6 hours, the motor lowered completely and raised fine several times. I will now drain the mystery oil and refill with hydraulic fluid. Being new to this forum and a 1st time user, I thank all of you that responded. Maybe this will help someone else. Thanks- Thumper 48