Yamaha 115HP Jet | F115JB Four Stroke Outboard

The Yamaha F115JB pairs a 115 hp four-stroke powerhead with a jet lower unit in place of a propeller, built for runs through shallow, rocky, or weedy water where a standard prop and skeg would be at risk. Sold new, it carries a 25-inch shaft, electric start, remote mechanical steering, and four cylinders displacing 1832cc, fed by EFI.

What the jet drive changes

A jet outboard pulls water in through an intake grate and pushes it out through a nozzle, so there is no exposed propeller, gearcase skeg, or cavitation plate hanging below the hull. That lets a boat run in water too thin for a conventional outboard, at some cost to efficiency next to a prop of the same horsepower. Owners moving from a standard outboard should expect a different feel at low speed and in tight turns, since steering comes from redirecting the jet thrust rather than turning a prop blade.

Fit and controls

The 25-inch shaft suits a taller transom; have that measurement on hand before ordering, since a jet unit cannot be trimmed the way a prop-driven motor can to make up for the wrong shaft length. Remote mechanical steering and electric start point this motor at a console-rigged boat rather than tiller control, and power trim and tilt are included along with the owner's manual.

Common questions

Can this run in very shallow water? That is the point of the jet lower unit; it is built to operate where a propeller would hit bottom or snag debris. Does it come with a propeller? No, the jet drive uses an impeller and nozzle instead. How fast does it spin at full throttle? Between 5300 and 6300 rpm, backed by a 3-year warranty.