When lifting mechanism starts to fail on Tohatsu engines are due to dried grease, salt, sand issues which jams the system. The tilting mechanism is not adjustable. What you need to do is lay engine down on floor with tiller facing upward. Tilt engine fully untill locks. Unscrew tilt stopper set plate (small plate with 2 bolts) that fixes tilt stopper onto internal swivel bracket body.
Once removed will find 2 half bushings, remove and fully clean them at both sides, once cleaned, grease both sides with water grease, clean tilt stopper arm to slide freely against greased bushings and set plate. Til stopper should be removed, cleaned and greased periodically during maintenance to ensure free and smooth tilt operation at all times.
If both half bushings are worn out or completely shot, install 2 new ones for tilt stopper to work properly. Check that springs are not missing.
Note: Before disassembling check how the tilting mechnism works, must be assembled back same way...
Happy Boating