Purchased 25 4 stroke new, replaced water pump in 04, 08, 09 and first time I started motor after winter storage for this spring the water pump is not throwing water. Engine stored on pontoon in full down position, all water drains from engine. Use water muff to check engine before I launch each season after winter storage - live in Michigan. In the past the muff has provided enough water to engine to pee water from lower unit. Any knowledge of water pumps being problem with this motor ? - all water pump units replaced by dealer. Thanks for any ideas.