My 87 60hp merc (3 cyl, 2 carb)has never had a very strong tell tale stream and after it had been stored for a few years I replaced the impeller and added a water pressure guage (0 to 15 psi). The guage will not even come off the peg at idle and at 2500 to 3000 rpm will come up to 2 or 3 psi...
