Motor is a 1985, new water pump has probably 1 hour on it. I rebuilt the carb and wanted to water test it so I put it in a barrel and cranked it up. A couple weeks ago I ran it in a lake and it peed fine the whole time. In the barrel it would not pee. So I dropped the lower unit, blowed air thru the pee hole, and took the water pump off to inspect. All looked perfect, as it should. I reassembled and put it back in the barrel. Started and it peed for a bit then stopped. Now it wont pee. Any clues/insight?