i bought the boat used and noticed one of the manifolds had a 6 inch crack on the outside of it with jb weld over it. i took off both manifolds and there is some rust inside. these are center rise exhaust manifolds with 2 outlet hoses leading to them. One pipe comes from the engine into the riser, and the other pipe comes from the engine into the bottom of the exhaust manifold. I put the manifold on the ground, upright, and put a garden hose on both hoses, then turned the hose on. Most of the water came out of the elbow leading to the Y-pipe while a few drops trickle into the exhaust ports. When i tested the other exhaust manifold, the one that WASN'T cracked, the same thing happened, a little water trickled into the exhaust ports. Is this normal or should no water at all be getting into the exhaust ports?