Yamaha Outboards 90HP VMAX SHO VF90LA. This powerful family now includes the all-new I-4 V MAX SHO 90, which packs the biggest punch of any 90-horse on the water. Overall, this series of 1.8- and 2.8-liter dynamos features a surprising tech package with 16 valves, single- or double-overhead cams and electronic fuel injection—for maximum efficiency and high performance.