2019 Yamaha 90 HP F90JB Outboard Motor

Rather than a conventional propeller, this F90JB drives water through a jet pump, pairing Yamaha's 1832cc inline-four 90 hp engine with a jet lower unit on a 25-inch shaft. Steering is remote mechanical and starting is electric, with a listed dry weight of 354 lbs.

Why choose a jet drive

Swapping the gearcase and prop for an impeller inside a pump housing lets a boat run through water too shallow or too full of debris for an exposed propeller, which is why jet units turn up on rivers, flats and similar hulls. The trade-off is some give-up in top speed and low-speed shove compared with the same engine on a conventional lower unit, so buyers chasing raw speed usually look at the prop-driven version instead.

Fit matters more here than on a prop motor: the jet intake draws cooling water differently, so hull clearance and mounting height deserve a careful look before ordering, and the 25-inch shaft calls for a taller transom to begin with.

Routine care matters more on a jet drive than on a prop motor: flushing grit out of the pump housing after use in sandy or silty water helps the impeller last, and a quick check of the intake grate before each outing catches debris before it causes damage underway.

Questions buyers ask

Does it include a propeller? No, jet drives replace the prop with an impeller inside the pump.

What steering does it use? Remote mechanical, meaning a console and cables rather than a tiller handle.

What's the warranty? A 3-year warranty is listed for this engine.