[Yachts]

Gen set overheated . Realized coolant was low. Added some coolant and everything was fine.
 I hadn't added any in 1000 hours of operating.. As a fellow guru who owns coach 512 but I want to keep his name anonymous once told me. " adding a liquid may temporarily solve your problem but it begs to ask where did the old liquid go.. ".  I see know signs of a leak so did I just lose some over time to evaporation?

[folivier]

One of the most common areas for a leak are where the filler neck is soldered to the tank. A few of us have had success by wire brushing that area clean and using JB weld epoxy to repair it. Or if you have time pull out the radiator and have a new neck soldered on at a radiator shop.
Do you have an overflow tank on the genset radiator? Easy to add one, most auto parts places carry them. The tank makes it easier to keep track of the level.

[Yachts]

Yes I have an over flow.. I'll watch it and keep track over the next couple of weeks. My generator is side mounted.