I recently purchased a 1955 QD-16 and converted it successfully to a single line fuel system (thanks to you guys) and i ran it in a barrel and it worked fine. i water tested it on my 12' jon boat and the impeller tore to pieces. the tell-tale or pee hole was under water since with my big butt and a motor on the back of my 12' jon boat made the back of the boat sit low and the bow high. I replaced the impeller and barrel tested it again and all good. my question is can i run an outboard motor with the tell-tale under water? i'm not sure if it was the age of the impellar, dry rot or wear that destroyed the impeller or if there was somehow enough back pressure or restriction that the impeller tore up. i don't want to replace another impeller if i don't have to. thanks in advance for the help.