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Hi, I have a Yamaha F60T outboard.
With the help of a local mechanic, I rebuilt the piston/cylinder on the trim/tilt unit. On the bench, the unit wouldn't work properly. It would extend the tilt piston properly, but when the polarity on the leads was swapped, it would only retract about halfway and then extend again. We spent several hours taking the piston and cylinder apart again, then checking and rechecking the assembly against the workshop manual/diagrams.
Everything appeared to be correct. So I bolted the unit back onto the mount over the weekend and was very surprised when everything appeared to work perfectly. Tested it out on the water this morning and still all seemed well so it appeared that it just needed the weight of the outboard to function normally. However, when I got back to the dock and hit a small blast of reverse, the entire engine tilted up out of the water. A manual check confirmed that the trim/tilt unit is providing almost no resistance against the motor tilting up. Tilting up and down works properly and there is enough resistance such that there is no movement when the unit is in forward gear even at full throttle.
We did not disassemble the motor/pump side of the trim/tilt unit. Before the rebuild, the trim/tilt unit was working faultlessly. (But the outer piston seal was torn, hence the rebuild)
The unit looks like this: https://www.boats.net/catalog/yamaha...im-tilt-assy-1
I have rechecked the oil level and the bypass valve screw.,
Based on what I've read, it would appear that there is an issue with the pressure release valve on the unit. I'm guessing this is the valve at on the tilt cylinder end screw (individually unnumbered in the parts diagram in the link above and also referenced in the workshop manual)? The mechanic did clean this out with some compressed air.
Would anyone have any thoughts on anything else I could check/try? Thanks so much!
With the help of a local mechanic, I rebuilt the piston/cylinder on the trim/tilt unit. On the bench, the unit wouldn't work properly. It would extend the tilt piston properly, but when the polarity on the leads was swapped, it would only retract about halfway and then extend again. We spent several hours taking the piston and cylinder apart again, then checking and rechecking the assembly against the workshop manual/diagrams.
Everything appeared to be correct. So I bolted the unit back onto the mount over the weekend and was very surprised when everything appeared to work perfectly. Tested it out on the water this morning and still all seemed well so it appeared that it just needed the weight of the outboard to function normally. However, when I got back to the dock and hit a small blast of reverse, the entire engine tilted up out of the water. A manual check confirmed that the trim/tilt unit is providing almost no resistance against the motor tilting up. Tilting up and down works properly and there is enough resistance such that there is no movement when the unit is in forward gear even at full throttle.
We did not disassemble the motor/pump side of the trim/tilt unit. Before the rebuild, the trim/tilt unit was working faultlessly. (But the outer piston seal was torn, hence the rebuild)
The unit looks like this: https://www.boats.net/catalog/yamaha...im-tilt-assy-1
I have rechecked the oil level and the bypass valve screw.,
Based on what I've read, it would appear that there is an issue with the pressure release valve on the unit. I'm guessing this is the valve at on the tilt cylinder end screw (individually unnumbered in the parts diagram in the link above and also referenced in the workshop manual)? The mechanic did clean this out with some compressed air.
Would anyone have any thoughts on anything else I could check/try? Thanks so much!
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