When operating a twin merc 500 on a 16 foot boat with a transom bracket, left engine was a lot hotter than right one (some 20 degrees centigreade). A mercury serviceman told me that in twin configuration one engine always gets hotter, and it is probbably because the outboards are with the short shaft. When operating them, i see that boath are in the water at all time, some 5 inches above the ventilation plate, and water runs good through the telltale pipes.
