1977 Evinrude 140hp Wont Tilt Down!

[spoon34]

Okay I bought a boat from a friend that needed a little bit of work. The tilt wasn't working at all at first, but my dad and I poured hydraulic jack oil into the cylinder and once we filled it up, the tilt motor raised the engine just fine. However, when pushing the tilt switch down, the motor will turn (sounds like it is stressing the motor), but it will not lower the engine. It lowers it about an inch, until the motor starts to sound like it is under pressure. The only way we know how to let the engine down is to unscrew the screw in the middle underneath the main valve and drain the oil. The screw on the lower left side of the unit has a brass springloaded sort of release device. I suppose it is used to let the engine down. We took it out, cleaned it up and oiled it up and the engine will still not lower. When we unscrew that screw as well, it takes a tremendous amount of force to unscrew it, even when we just barely tighten it. When we release oil from the unit, there is also a bubbly/fizzing sound like there is air in the unit, which I'm sure there is. Is this a problem? Can anyone help this problem??

 

[HighTrim]

Re: 1977 Evinrude 140hp Wont Tilt Down!

That is called you manual release valve. The system is self bleeding. First make sure that your motor is reversing. If so, what you need to check next is a couple of valves that may be blocked. The first is on the port side, the left side looking towards the back of the boat. If you look beneath the motor, there will be 3 pressure test points. In between the first and second will be the first valve you need to check. What you are looking for is full and free movement of the core, no clogged outlets, and no dirt or chips in seat area holding the valve open. The second valve is also under the motor, in line with the second pressure test point (the middle one), after it turns in an elbow (90 degrees). If they check out, check the pump face for dirt or heavy scratches, the pump is below the motor. Check the manifold face for dirt or heavy scratches. There is also a filter valve in line that comes off the tilt cylinder and goes to the resevoir cavity. Remove this and check for o ring cuts, chips out of or cuts in seat, metal chips or dirt on seat. I tried to list these in order of most likely culprit. Good luck.

 

[spoon34]

Re: 1977 Evinrude 140hp Wont Tilt Down!

Thanks so much for your advice! I'll check it out here in a few days!