Starting up port engine that was winterized (crusader 454 xl) in a Carver 1997 355 aft. The engine starts up great and runs for about 10-15 sec at idle but then starts to stall and then does stall. Fuel was stabilized for winter. Have tried to make all filters ok, bypassed tanks and used 2-3 gallons of new fuel and same symptom. These engines gave us no problems last year. Boat maintained and in excellent condition. The only thing that we forgot was to put fuel separator filter on before starting the first time. That has been remedied. Fuel pump appears to be working.