C
Chuck Drake
I bought my 460 18 months ago and have not been able to exceed 2800 rpm's without overheating my Yanmar (max is 3700). Every inch of the raw and freshwater system including strainers, impellers (new twice), heat exchanger, mixing elbow, etc, have been checked and rechecked as perfect. Raw water flow is excellent and the mixing elbow remains cool to the touch throughout the rpm range. I had a local Yanmar dealer come out and test everything today using a cool laser temperature probe. They are of the conclusion that the exhaust routing between the engine and water lift muffler may have a droop allowing too much standing water in the hose causing too much back pressure for the exhaust. We are going to step two asap and test out that theory with different test equipment. In the mean time, has anyone else been thru seemingly unsolvable overheating problems on this model?