Yamaha T9.9 Outboard Tilt Trim issue

[Brian.D]

Hi guys. I know you are big boaters but some of you might have a tiny outboard for your dinghy. My issue is related to the manual valve release screw found on Yamaha outboards with Tilt and Trim hydraulic systems. Here goes.

A couple of years ago I had an issue (same as right now) where the motor was stuck in the up position. At that time I didn't know about the manual valve release screw. I asked the guys who did the bottom cleaning if they could get the motor down. After that I went to the boat and found my motor tied in the up position. After releasing, the motor worked. So I suspect they knew about the manual valve release screw.

Well, I have been away from the boat for awhile and again, the motor is stuck in the up position. My problem is I don't know much about the release screw. I know it needs to turn CCW but by how much. Right now, it does turn but only 90°. I have seen on videos that it needs to be turned several times. The service manual says 90°. So I don't know which is correct.

Since it does turn 90° but the motor does not move downward, I must assume that it need more turns. That is the problem. I cannot budge the screw anymore. I have tried an impact tool but in order for me to get to the location of the screw, I am practically upside down. I have two options to access location: use a dinghy or move the boat to stern in first.

Now, the question is should I expect more turns on the screw? Or is the 90° turn enough. Hopefully I can get an answer from someone who has done this already. The motor is from 2011 and model T9.9XPA.

Thanks in advance

[Jammer]

Good luck, Brian. I have sold my 2010 T8 which had the same arrangement, and never had to use the emergency screw. If you were able to turn the screw 1/4 turn before it started binding, you should be able to get at least some flow. If you have not already done so, perhaps allow an hour or overnight. My T8 tended to leak past the pump/valve seals and would drop an inch or two overnight even with the screw closed.


Good luck

[Brian.D]

Thanks, Jammer. Hoping someone has experience with the manual valve pressure release.