Yamaha Power trim and tilt

[Waltg1296]

1999 90 hp yamaha power trim will not lift engine or lower engine.. The trim motor runs when the switch is in the up or down position, the engine does not move. It had been working very slowly up until I tried to check the fluid level. The pressure in the reservoir caused the fluid to bubble out when I removed the filler screw. I have refilled the reservoir and tried to bleed the air out. Only occasionally can get the trim cylinders to go up and down a little bit. I usually have to use the release valve to lower the motor. Could this be as simple as a solenoid? Although when you hit the switch, you can hear the solenoid click and the motor does run and sounds like it did when it did work. Also, the tilt cylinder will not move at all. Trying to rule out bad solenoid, bad trim motor, or is there a valve malfunctioning. If so, does that mean a new power tilt and trim assembly?

 

[rodbolt]

Re: Yamaha Power trim and tilt

bythe fact the trim motor works you just verified the solinoids,motor and switches.
now we have to look and the hydraulics.
most likly a manuel release valve failure but its possible one of the main valves is stuck or broken.
try replacing the orings and valve,if that does not work then dissasembly of the unit will be required.
the engine must be full up to check the fluid level.

 

[Waltg1296]

Re: Yamaha Power trim and tilt

The boat mechanic I took it to today indicated that it might get expensive for him to diagnose the problem and he recommended that I replace the entire assembly. He was going to see if he had a used one off an old blown motor. He indicated that to replace the assembly, he had to take the engine loose from the transom.
It looked to me that the assembly should be able to slide out without having to remove the engine from the transom.

Is the valve located under the large flat head screw on the hydralic pump? There is anonther screw on the left front of the resevoir, is this where another valve is? Are these under pressure and aren't there some springs and gaskets that will come out when i unscrew them? The manual release valve seems to function as it should as when I do get the trim to go up a little, I can turn that valve, and it will lower the motor back down. Thanks for your help!

bythe fact the trim motor works you just verified the solinoids,motor and switches.
now we have to look and the hydraulics.
most likly a manuel release valve failure but its possible one of the main valves is stuck or broken.
try replacing the orings and valve,if that does not work then dissasembly of the unit will be required.
the engine must be full up to check the fluid level.