After a grueling 10-hour back operation 2 years ago and subsequent recovery (and several other distractions) I'm just about ready to start my "new" boat up. I've replaced the raw water impeller and the hose from the transom to the impeller is clear. However, when I connect a water hose from the house to the raw water pickup at the transom (the drive is removed), nothing flows. Actually, it pressurizes to house pressure and blows the hose off. I expected it to flow through the impeller and thermostat housing and out the exhaust. I'm afraid to start the engine is the cooling system is blocked somewhere. Does this sound normal or blocked? Btw, my boat is a 1998 Glastron GS-249 cruiser with a Volvo Penta 5.7 GS PBYC and VP SX-C1 Cobra 1:51 outdrive (currently removed).