73 evenrude power trim tilt question..

I picked up a 1973 AMF Crestliner(16') from an friend who had passed away.
This guy was was one of those guys who kept every thing perfect. The boats in original condition and looks brand new.. It was always covered and kept inside.. It has a 115 evenrude on it that runs awesome and pushes it very nicely.

My only issue is with the factory even-rude power trim power tilt.
When I got it it didn't work. some one had a ground wire hooked to the positive side and the solenoid was shot. I fixed all that and it works great now except when I put the engine all the way up. It kind of jams and gets stuck and will not come down. The only way I have gotten it to come down is to release the pressure in the pump just slightly then the motor will bring it down...

What the deal with this. I tried to bleed the air out and it seams like I got it all but doesn't make a difference.

Any help would be greatly appreciated.

Re: 73 evenrude power trim tilt question..

I have a 77 evinrude and I rebuilt the tilt cylinders and they work great, I never had that problem but the the cylinders may need rebuilt, if you decide to do that let me know, I know a little trick puting them back together that will save you money and greif.

Re: 73 evenrude power trim tilt question..

They work great. It just that they get stuck in the full up position. For me its not that big of deal because I usually put the engine up far enough to drop the engine rest down and then I lower the engine down on it and im good. But occasionally I let some one use the boat and tell them before they take it to make sure and not raise it completely and it never fails. I get a phone call a few hours later because they cant get the engine to come down..

I'm thinking that the issue is in the pump and theirs some sort of check valve that's not releasing but that wouldn't explain why it works fine unless its goes all the way up or some how their might be air in the system..

I have worked with a lot of hydraulic systems before just never anything this small or of this type..
The boat did sit for along time before I got it so maybe just a sticky valve or something..

Re: 73 evenrude power trim tilt question..

some system get a type of pressure lock if they go too far up. The slider inside works on a pressure differential to open check valves. If you keep running the switch even after it is all the way up then you get too much pressure for slider to slide and ... ta dah! pressure lock. You can loosen a nut and let just a drop or two of fluid out and the pressure lock is broken. Some system have a manual release fitting that does same thing. Just be careful not to wallow out your manual release. A tilt limit switch is the best solution (if this is your problem).