I just purchased a 2004 Merc 15hp that has never been used. A gentleman bought it back in 04 with good intentions but never even started it up. I put it in a barrel of water to fire it up and noticed a weak pee stream. It gets stronger when I give it a little throttle but very weak at idle. Is that normal or could the impeller have dried up? I have a 90 Mariner that has a strong stream even at the lowest idle. Thanks for any input.