I have a 5hp Johnson Model J5RSS made 11/99 which has decided to stop pumping any water. It seems to blow a fair bit of air out the telltale but no water. I'm assuming this is the impellers fault. I tried today to drop the lower part of the leg off it with the engine upside down but I can only get it to come out about 2 inches. I undid almost every bolt I could find but it made no difference. What is the tecnique for getting the gearbox out? It was in neutral and I jiggled it a fair bit without getting too violent. thanks...