I am concerned about the future availability of green coolant. I have a 2000 Kohler 5e marine generator , powered by a liquid cooled Kawasaki FD501D twin cylinder OHV engine, 16 hp of 437 cc displacement. I have always used green coolant, and it is the only machine I own still using green. Marine generators are expensive, and I do not want to do anything that may damage the engine. Should I worry about the future availability of green coolant and consider switching to something else ? Or is there a newer coolant that is completely compatible with the green stuff ?