HAVE A 1985 FORCE 50HP MADE BY USMARINE. IT RUNS GREAT. STARTS UP WITH 1/4 TURN. THE PROBLEM IS THERE IS NO POWER. LUCKY IF MOVE THE BOAT 5 TO 10 MPH . I HAVE A 16' FIBERGLASS BOAT.V-HULL. THE PREVIOUS OWNER SAID IT WOULD PULL A SKIER WITH NO PROBLEM.? MOTOR SAT FOR 5 YEARS UNDER COVER. HAD NEW...