1989 70HP Yamaha Tilt/Trim Prob - won't go down

[TelSupply]

A couple months ago my 1989 70HP Yamaha would not go down once in a while, I would click it a few times and it finally would go down, Up worked ok and continues to work fine. Now, the Down won't go down at all. Yesterday, I "could" hear the motor trying but still no luck. I tried it over and over for about 5 minutes and now the motor doesn't even make a sound.

What do you think it is?

Is there one motor for up and down, or is there one for up and one for down?

People say check hydraulic fluid? Solenoid?

Please advise...

 

[99yam40]

Re: 1989 70HP Yamaha Tilt/Trim Prob - won't go down

one motor
get a service manual for your motor and read it.

Do a forum search on tilt and trim problems

 

[RRitt]

Re: 1989 70HP Yamaha Tilt/Trim Prob - won't go down

if it was an american made motor i would say go buy yourself a new pair of those $3 relays and put them in. But since it is a Yamaha then your relays are $40+ each and it doesn't make sense to just throw them out for a new pair. Kind of shame. It's same part and everything. Yammer isn't any better, just different wiring connector. But it is what it is. So try hot-wiring the motor. If the motor runs when hot wired then your relays are probably bad. If not, then its probably your motor. Fluid is not intermittent. Intermittent problems mean electrical.

 

[TelSupply]

Re: 1989 70HP Yamaha Tilt/Trim Prob - won't go down

Thanks for the info. I have noticed that sometimes the relay doesn't "click" so I will swap the Up with the Down and see what happens.

 

[TelSupply]

Re: 1989 70HP Yamaha Tilt/Trim Prob - won't go down

I swapped the relays and the motor engaged for "down" but it still did not move the motor. Could it now be a lack of hydraulic fluid?

 

[TelSupply]

Re: 1989 70HP Yamaha Tilt/Trim Prob - won't go down

If I do need to add fluid where do I add it. One of the "cylinder" looking pieces have an easy to remove bolt half way up it, is this the place to add the fluid?

 

[RRitt]

Re: 1989 70HP Yamaha Tilt/Trim Prob - won't go down

If I do need to add fluid where do I add it. One of the "cylinder" looking pieces have an easy to remove bolt half way up it, is this the place to add the fluid?

most trim systems have to be raised in order to add fluid. a 1950's style katsup squeeze bottle is probably the best tool ever made for filling trim systems. You may need to tie a rope around the prop and throw it over a rafter to help the engine up while pressing the switch.

low fluid rarely causes a "down" failure. Gravity pulls the engine down so all you really need is enough fluid to activate the check valve poppet ... about a tablespoon.

 

[TelSupply]

Re: 1989 70HP Yamaha Tilt/Trim Prob - won't go down

Well, I got a tube of fluid and filled up the reservoir. The motor spins (makes sound like it's working) but did not go down, or even up at this point. I did try the manual drop but couldn't remove the screw (stripped long ago). I did loosen a couple of those whacky aluminum tubes which cause a slight enough leak that by this morning the motor was in the down position. I tried to get it to go up and it would not. What am I missing? Not enough fluid? Air in the system? I even bought a maintenance manual! Any ideas???

 

[RRitt]

Re: 1989 70HP Yamaha Tilt/Trim Prob - won't go down

If the motor was removed then it is possible the the motor shaft is no longer seated into the drive gear. If you did not take the motor off trim system then that is not possible. In which case, you've blown a piston seal either in the valve body or in the cylinder. Other problems tend to be in one direction or another. Complete blow-by in both directions is more or less a complete failure and the best long term course of action is a full rebuild and never worry about it again.

I would bet that yamaha doesn't sell critical seals separately. Why sell a $0.25 seal when you could sell a $100.00 poppet kit instead? They aren't stupid you know. So maybe you should take the system off of your boat and drag it into the nearest road grader & bucket truck hydraulics repair shop. They sell seals for $0.25 each and maybe even have a service center that can fix you up for dry-land prices.

 

[TelSupply]

Re: 1989 70HP Yamaha Tilt/Trim Prob - won't go down

Ha! Nothing is easy...I'm to the point that I don't want to waste anymore time on it. I may just buy a used one and swap it out, then fix that one as a project and sell it later. I did the same thing with my lower unit. Thanks for your help.

Quick question: the motor is in the Down position now which will get me to the ramp. Once on the trailer how can I get it to go Up so the lower unit doesn't hit the ground, will it push up manually? Or, I was thinking on throwing some extra 2x4's on my trailer bunks to raise it up, what do you think?

 

[RRitt]

Re: 1989 70HP Yamaha Tilt/Trim Prob - won't go down

on my shop load testing stand i have a fairly long section of galvanized rigid pipe strapped onto the swivel. It's kind of like third world tilt. I bet it would be fairly easy to rig it up on a real boat.

If you haven't worked on hydraulics before then save yourself the aggravation and let Joe's House of Hydraulics rebuild it for you. Rebuilding hydraulics so that they last is harder than rebuilding an engine. Once you get into the pumps it is more like watch repair than automotive.