I just bought this motor this week. It's a 1996 Mariner 40hp. (C40ELHPTO) I was wondering what this hose coming from the lower unit is for? I was told that the motor was just serviced and ran just fine. Any idea's? Thanks
That would be the pitot tube pickup for a speedometer connection. I never used mine so I removed it when I did the waterpump service on the LU.
There will be a threaded plastic fitting attached to the hose that threads into a boss in the LU. Simply unscrew it and install a 1/8" (I think) pipe plug in its place if you don't need the pitot tube.