Merc 40,50 and 60 hp 4 strokes are built in Fon du Lac, WI. The 30 hp and smaller used to be Yamaha, but have been Tohatsu since about 2005 (don't remember exactly what year).4 stroke or two? what size? mercury completely absorbed force by 97 or so, but merc has never built a 4 stroke smaller than 75 hp. Those are all yamaha powerheads.