My experience is both with the coupling unit and the mirse teleflex command located at the inside helm station.
1- coupling unit : I experienced very hard to manoeuver morse command. To track down the problem I disconnected the cables at the couling unit. One comes from the outside helm, one from the inside helm and the last one runs from the coupling unit to the inverter gear box. I was then able to manoeuver them by hand and discover that the last one was a bit stiff : someone’s foot had put pressure upon it at the gear box level and bend very slightly the end of the cable, which is more than enough to build friction and make forward/backward almost impossible. Cable changed and every returned to normal.
2- from time to time it was impossible to switch from backward to forward or vice-versa, handle was stuck in opne position. Not confortable to manoeuver in marinas. Procedure described above in 1- would not help. Eventually the cable broke right inside the morse command at inside helm. Changed the cable and was faced with problem 3, solved.
3- alignement at engine control lever : after changing the morse cable between helm and coupling unit the handle would not allow faster than 1700 rpm. I discovered that someone’s foot and weigth had bent that piece of metal close to the speed control on the engine, thus command cable sleeve and engine control lever were no longer aligned. un-bending and Realinging that piece of metal solved the problem.
Just in cas all those misfortunes help someone else.
Yves.(NC33 1978 Naïla)