Was the boat located in a place that actually has a winter season?
I haven't heard of pink diesel fuel in boats, either. Pink and oily fluid sounds to me like it could be the antifreeze used to winterize a boat's water and waste systems. These are drained as best as one can in the fall, and pink antifreeze is then flushed down the head, as well as dumped in the water tank and pumped through the kitchen and head sinks. A leak in the water or waste system could be responsible for antifreeze getting into the bilge. I suggest inspecting the hoses and tanks. Also, it is entirely possible that the previous owner dumped antifreeze directly into the bilge. I've never heard of anyone doing that, but it is possible.
My fuel tank has four hoses. There is the deck fill. There is the main fuel line that connects to the primary fuel filter near the engine. There is a fuel return line running from the injectors back to the tank. Last, there is a vent hose. This runs from the tank to a vent located on the stbd side of the transom. I've had issues in the past where the fuel tank was too full, and pitching of the boat ended up pushing fuel out the vent line, making a mess on the transom. I don't know what you mean by fuel spilling out the overflow; if you're referring to the vent, then it should be connected by hose to a vent through the hull or transom. If there isn't a hose connected to the tank's vent fitting, then I'd strongly suggest fixing this.
These are old boats. I've found that the fuel hoses in mine were leaking. Engine vibration rubbed them against the fiberglass hole where they pass into the engine compartment, causing them to chafe and leak. I replaced them, and lined the hole through the fiberglass with rubber hose to make an improvised gasket. This chafed through the battery cables on the port side as well.
Good luck!
Ryan
Tesara, #337
