Yamaha F90 Jet Drive

The Yamaha F90 Jet Drive represents the ultimate choice for boaters requiring high-volume water displacement and heavy-duty, shallow-water capability. By replacing a traditional lower unit gearcase with an advanced hydrodynamic jet pump, this outboard eliminates any protruding skeg or propeller, allowing your hull to skim safely over rocky riverbeds and hidden shoals. Because jet pumps experience an inherent parasitic power loss of roughly 25% to 30%, Yamaha leverages its massive 1.8-liter powerhead to blast a highly effective 65 horsepower directly out of the jet nozzle.

The secret to this engine’s immense lifting power is its large displacement block. Built as a single overhead camshaft (SOHC) inline-four with four valves per cylinder, it offers significantly more torque than smaller mid-range platforms. This massive displacement enables the F90 Jet Drive to pop heavily weighted aluminum jon boats, commercial workboats, or large flats skiffs onto a plane almost instantly. Driven by precision Multi-Point Electronic Fuel Injection (EFI) and a microcomputer ECM, it delivers razor-sharp throttle response and turnkey reliability in isolated, fast-moving waters.

Models Available:

• F90JA — High-performance remote mechanical configuration engineered for console-steered river runners and technical flats skiffs. Features electric starting, power trim and tilt, and a specialized short midsection optimized for jet-transom mounting heights.

Key Features:

• Powerhead Displacement: 1832cc (1.8L) inline 4-cylinder four-stroke (SOHC, 16-valve)

• Output Rating: 90 HP at the crankshaft / 65 HP at the jet pump nozzle

• Propulsion System: Outboard Jet Pump (Completely flush intake shoe)

• Control Type: Remote Mechanical (Traditional throttle/shift cables controlling the jet gate)

• Fuel system: Multi-Point Electronic Fuel Injection (EFI)

• Alternator Output: 35 Amps (Substantial charging capacity to run multi-graph sonar networks, high-output LED light bars, and baitwells)

• Weight: approx. 165 kg (364 lbs)

• Advanced Phaze Five™ multi-layer anti-corrosive paint array

• Single electronically controlled throttle valve for precise fuel-to-air delivery

Ideal For: Large aluminum river boats, technical tournament bay skiffs, shallow-water rapids navigation, commercial utility workboats, and heavy-duty jon boats.