AS INDICATED FROM THE CURRENT OWNER; The reason for low hours on the 1996 Mercury Engines is that they had just been overhauled (i.e. new pistons, rings, etc.) when I purchased the boat. After an overhaul, those engines need to be broken in as if they were new again. The breaking in period consists of running the engines at various lower rpms (less than 5,500 rpm) for 10 hours or more. I followed this procedure for 12 hours and then winterized the boat for storage. No receipts for the overhaul as the engines were overhauled and mounted on the boat hull before I purchased the unit.