1978 Johnson Tilt /Trim issue, Won't go down. Help?

[MPAdams]

Hello! Newbie Here... I just picked up a bass boat from an old bass-pro's estate. It is a 1978 Monark McFast with aJohnson 115 outboard, I have a problem with the tilt/trim system. It tilts up, not down. Tilt motor runs but no real movement down, and the tilt motor sounds strained trying to go down. Works great up. I can use the pressure release screw and it will go down but only to the Trim rods, and they do not move either powered or using release screw with downward pressure on engine. I can not get the engine to drop the trim cylinders at all. I have filled the reservoir and cycled it up/down multiple times to bleed unit. Does anybody have any ideas?

From viewed from the back the Tilt/Trim unit has motor on left, reservoir on the right the tilt cylinder in the middle and on each side of the lift cylinder is a trim cylinder(2 total) the Model number of the Trim unit on the outside of the mounting bracket is 115etL78c and the serial number is j4980804.

Any help would be appreciated.

Thanks,
MP

[ChampioNman]

It maybe in the solenoid itself. If you swap the green wire to the blue wire's post and vice versa you could test it that way. The trim relay assembly is/should be mounted inside the boat, probably attached to the inner transom wall.

[MPAdams]

Thank you ChampioNman!
The motor runs in both directions. When moving engine up, motor spins fast and engine moves. When trying to lower motor, motor spins but sounds strained and engine does not move. Do you still think it could be the solenoid? I haven't tried your suggestion yet because it's 110 degrees outside... waiting for it to cool down a little. Thanks!

[ChampioNman]

More than likely due to age the trim units internals would need to be torn down and repaired due to age..It is a very old system and the internals would need to be disassembled and cleaned and put back together.

[MPAdams]

OK... switched the wires and the only thing different was I hit the down button and the motor went up. I hit the up button, the motor spins but the engine doesn't move. To clarify, everything was the same but the switch behaved opposite.

Do you think someone mechanically inclined should attempt to tear it down and clean it? I have purchased the shop manual recommended on this site and am trying to find something in the manual other than the suggestion to take it to the shop. Thank you again! MP

[JR19]

I think if your Johnson has been up more than 4 hours you should seek treatment.

[ChampioNman]

If you are mechanically inclined you can tear it down and using the manual and parts diagrams to rebuild it.

[MPAdams]

I am very frustrated this morning. I purchased the "shop" manual for this motor (found link on this forum), and the manual said that if I had problems with the trim/lift to take motor to dealer for repair. It does not give a parts diagram or break out. I figured I must have made a mistake when I chose to purchase the "shop" manual instead of the "repair" manual... so I purchased the repair manual. THEY ARE THE EXACT SAME MANUALS except the repair manual is missing some of the pages the shop manual has. So I have spent about $20 already and I'm not getting anywhere. (I remember a time when $20 bucks was nothing. These aren't those times anymore! LOL)

Does anyone have a diagram of the hydraulic break out for this motor? I have searched online and can't find one. THANK YOU!

[ChampioNman]

The parts diagrams are not part of the service manuals. You can refer to any of the online parts retailers or www.shop2.evinrude.com you need to select your model year and then follow the drop down menus to select your exact model. You can also use www.boats.net or www.marineengine.com. Those will provide you with the breakdown of all the components in the trim system. I guess I should have been a little more specific.

[MPAdams]

THANK YOU so much, ChampioNman, for your quick and helpful suggestions!!! I will head over to these websites right now.

[omcforever]

THANK YOU so much, ChampioNman, for your quick and helpful suggestions!!! I will head over to these websites right now.

[MPAdams]

Arg! This model number (115etL78c ) is not listed as an option on any of the sites you suggested. I did find one site that listed this engine as being made for the saltwater environment. Do you have any other ideas of where I could get a parts break out? THANKS!

[omcforever]

http://www.boats.net/parts/search/BR...RIM/parts.html

[MPAdams]

This is a 115TXL78C ... is that the same motor?
Reason I'm asking... this shows that there are two springs on either side of the direction shuttle on this diagram. There are no springs in my tilt/lift unit... so they are either missing or not the right motor. I see that there is a 1977 that does not have springs... but it also is not the correct model number.
Thanks for your patience!

[omcforever]

1978 doesn't list a 115TXL78C,,,double check your plate on the motor but it is the same.

[omcforever]

Maybe ETZ

http://www.marineengine.com/parts/jo...+Tilt+And+Trim

[MPAdams]

I am absolutely sure. Re-checked more than once. Here's the link I found that describes this motor: http://boatspecs.iboats.com/Johnson_...78/bpe/57e7784

[ChampioNman]

Doesn't matter the trim unit is exactly the same. They don't have a different unit for a L or X shaft, the midsection is the same.

[eh2000]

Did you troubleshoot or replace your relay? I had a fun event driving down the lake one day where my tilt/trim would only go up...turned out to be a bad relay.

[MPAdams]

Yes - trouble shot and disconnected the relay. The down direction to the drive does not use relay - it is direct.
I bypassed the controls and went straight to battery - motor pumps both directions. Down direction does not move drive.
I disconnected hydraulics to lift cylinder - it pumps fluid to both directions.
Additionally, trim plungers do not move - they are stuck in up position.
My thought is that it is probably a check valve and/or bleed down is stuck.
My plan is to pull the lift assembly off the boat and remove each valve and clean and try again.

Do you know what valves do what functions?