Re: Force ourboard tube from lower unit.
If it is a black rubber tube, It is a speedometer connection. Later Force engines made by Merc had a small pitot (impact) hole in the front of the lower unit about midway down between the cavitation plate and gearcase torpedo. This connected internally to the rubber tube and that tube connected to the speedometer tube. If your speedometer (assuming you have one) was installed with its own water pick-up, then the engine one was not used. If you do not use it, then just tie it out of the way--no harm, no foul.
