Re: merc 50hp no water comming out pee hole
L/U HAD to be removed when you blowback air if you want the pieces to exit the system.
While removed, check that the key is in place on the driveshaft and, when you replace it, make sure that the water tube is lined properly.
BTW, on 1990-current inline 3, there's no water cover to access the water passages...