I have a 888 pre-alpha leg and I was wondering if I need the impellor in my leg if I have a through hull raw water pump. The water line from the leg is isolated, and not part of the through hull system which cools the block and dumps through the exhaust. Some people have told me that I should use both since the leg impellor circulates water in the leg and cools it, and others have said don't bother with it. Since the water from the leg impellor is not used for cooling the block and the water flow in the leg seems to be dead ended am I needlessly pressurizing the leg? Am I putting pressure on the seals in the leg? I now have the leg apart to reseal the upper unit which was leaking into the bellows and was looking for some guidance before I reassemble it.