Cross Over Tube Between Thermostat Housings

[Fair Well]

Started boat up today to make sure every thing ok for trip to haul boat next week. Wouldn't you know after about 20 min. running started smelling antifreeze! After looking for the source (was hopping for a bad overflow bottle or radiator cap) found a pretty good stream of water running down the front port side of the port engine. This is the engine that was overhauled 4 years ago in FL before we brought her back to TX. The cross over tube is eat up. The inside of the thermostat housings are black. My question is what caused this? The mechanic said he put corrosion inhibitor in at time of overhaul. The engine has around 145 hours on it since overhaul. Is this normal after 28 years or do I have a bigger problem. I tasted the water and it wasn't salty (yes I know I shouldn't have) Water I drained out was clear with a slight violet color. The antifreeze was purple that accounts for the violet color. Any suggestions

 

[Regal2800]

the engine is 30 years old and sitting in a corrosive environment. These tubes are relatively thin, and rusting through is not uncommon. Depending on who did the overhaul, they are not always noticed or replaced during an overhaul. I know i have had to change a few of these pipes on mine.

DD makes test strips which you can check the coolant condition.