I recently came by a parts motor that I need help with. It is a 2.4 bore size, 5805925 stamped on the welch plug, on the port side next to where the intake bolts are 12191 or possible 12181 in the same area UD 6 20 0 is stamped. Head bolt bosses are on the side of clyinder and it has 2 piece heads. The clamp is a Mariner and the number is A183393. I am trying to find out the year and HP of the motor and clamp. I have checked some parts sites and they tell me serial # not found. Any help would be appreciated. Thanks