Any Tohatsu Experts?

[C08]

My power tilt declined to raise recently. As I was on a pontoon the was rapidly drying out I had a bit of a panic as I did not want the weight of the boat on the outboard leg, although the rudders would take most of the load. Having done a quick check of the electricals I decided in the time available I should release the screw on hydraulics on the tilt leg to manually raise the leg. Well this screw is on the waterline and even lying in a dinghy it was impossible to shift with a large screwdriver and a mole grip. I think this screw is a plastic plug perhaps very tight to stay in position. In theory 3 turn anti clockwise should have released the locked leg. Having failed to do this I tried the wires again and it was just a poor connection on a bullet connector.
However earlier in the day I had sailed to Selsey Bill from Brighton leg up and then lowered the leg to motor to through the Looe Channel to Portsmouth with strong winds then on the nose. If the leg had locked in the up position I would not have been in a good position to tack to starboard due to the shoals, to port yes but I really wanted to get to some shelter and going back to Brighton would have been wind over tide and hard to enter Brighton under sail with that wind direction, Littlehampton out of water so not attractive options under sail, and my boat is not very good on the wind.

So experts is it possible to replace the manual/auto screw with a bolt as then it would be possible with the leg up to reach down with a socket and ratchet spanner and release the leg. I can see the thread not being a problem but how to lock it in position and how to stop any leakage either way. Engine is a 20HP MFS auto tilt.

 

[C08]

Had a response from Tohatsu UK straight away. They acknowledge the poor design and the difficulty of accessing the pressure relief screw to manually lower the leg and are well aware of the problem. The tilt/trim motors are made by Showa who apparently do all the Japanese power tilt units. The screw is actually a valve with a number of O rings on various diameters, with a hole across the end and a groove for a circlip to retain the plug so something made of metal will be complex. The advise keeping it greased with a Quicksilver Grease with PTFE in it. Looks like an end of season jobbie. Tohatsu refreshingly frank and helpful and sent me workshop manual (266 pages) and the Outboard parts list which has very good exploded diagrams.