The current model 25 and 30's share a common powerhead, and are made by Tohatsu for Mercury. I may be incorrect in my stating that a 4 year old 15 fourstroke was made by Yamaha, but earlier 15 and 9.9 fourstokes WERE Yamaha's. I need to check to see when Tohatsu started making these motors for Mercury. On a side note, all Mercury motors 30 horsepower and under, are NOW all built by Tohatsu. I think I may stand corrected Star, hats off to you.