I have been working on getting rid of boat smells on my 1985 H28.5 for over a year now.I am convinced the smell that lingers comes from our 2GM diesel. I have replaced some but not all hoses. The smell is kind a mix and not really a fuel smell, maybe somewhat exhaust related. It is worse anytime we have run the engine. I do not find any leaks in any of the hoses or on the engine. I did install a lower that we use when motoring but the odor will affect the boat when not being used. Like I said it is not really a fuel smell. Any ideas.Jeff