The 75 engine of yore is a 3 cylinder engine. These were small cube engines of only 49 cubic inches. A "high port" engine, it was a dog out of the hole (not a lot of torque) but loads of high rpm capability. Would work good on a really light boat. The 20" shaft engine weighed 248 and the 15" short shaft engine weighed 198. Some time in the late 80's the displacement was changed to 56 cubic inches and only sold as a 70. It's got some low end grunt. The big brother 4 cyl crossflow was nearly 100 cubic inches and came from 85 to 140 hp. right at 300 lbs. As far as I'm concerned the V4 will run circles around the 70/75. Today's hp comparable 4 stroke engines are heavy compared to the old 2 strokes.
