So I’ve got a 15hp Mercury it runs fine tool the leg of tested it in a bucket with a drill and got a good spray of water from the water pump also checked impeller while it was off. Put some air through the copper intake pipe and there’s air coming through. Put it all back together tried it in a bin of water and got no water through the pee hole. Added more water up to where the exhaust holes are and got a nice steady stream through the pee hole. Can anyone tell me what’s going on I made doubly sure the copper inlet pipe went back in the water pump correctly. If anyone can help would be greatly appreciated.