Hi, I have a 1998 Searay Express cruiser with a 2002 Mercruiser 5.0 EFI (Quicksilver Reman) , Anyway, I just drained all the water out (2 Block drain plugs, 2 Exhaust manifold plugs, Pwr Steering cooler plug), I'm now reading that there may be a 6th plug to drain the "cool fuel" system? Can...