afaik, this engine was an adaptation of half a sport bike engine to compete with the GS. Hence the cross-plane crank and shim under bucket valves.
What we forget though is that Yamaha builds engines for boats, personal watercraft (jet skis), their RMAX unmanned helicopter, a line of quads, other vehicle manufacturers (incl Ford), water pumps, industrial engines, etc. The engine may have been meant to be used in one of those originally.
What we forget though is that Yamaha builds engines for boats, personal watercraft (jet skis), their RMAX unmanned helicopter, a line of quads, other vehicle manufacturers (incl Ford), water pumps, industrial engines, etc. The engine may have been meant to be used in one of those originally.