Yamaha 90 Outboard Engine

Yamaha 90 Inline 4 1.8 L

McMichael Yacht Yards & Brokers is an authorized Yamaha dealer. With a legendary 97% reliability, they’re one of the most trusted outboard brands. Yamaha combines reliability, durability and long range fuel economy throughout their award-winning outboard engine line.

Boats Powered by this Engine: AB Oceanus 17 

Inline 4 1.8 L 90 HP

The 1.8-liter I-4 F90 features greater displacement and a single-overhead-camshaft design with four valves per cylinder. This boosts power and volumetric efficiency, streamlines design, and makes the F90 a leader in torque and acceleration.

  • Only 353 pounds
  • Available in 20” or 25” shafts
  • Powerful 35-amp alternator
  • Prop Shaft Horsepower:
    90hp at 5500 rpm
  • Displacement:
    1.8 L
  • Full Throttle RPM Range:
    5000 - 6000 rpm
  • Starting System:
  • Gear Ratio:
  • Alternator Output at WOT:
    35 Amp
  • Weight:
    353 - 362 lb
  • Shaft Lengths:
    20", 25"
  • Recommended Fuel:
    Octane 87
  • Power Trim:
  • Engine Type:
    Inline 4
  • Warranty:
    3-Year Limited
  • Fuel Induction System:

Power And Performance

Powerful Hole Shot

The Composite Intake Manifold on F90 features a long tube intake tracks, tuned to increase airflow, which boost low-end and midrange torque. This means a more powerful hole shot and increased acceleration. Even with all this responsive power, an air silencer box and surge tank reduce air intake noise and air turbulence for smooth, quiet operation.

Power and Efficiency

Precision Multi-Point Electronic Fuel Injection delivers the exact amount of fuel needed for optimum performance and efficiency. Yamaha’s EFI optimizes fuel atomization further enhancing fuel economy.

Lightweight, Compact Design

The F90 features a single overhead camshaft, but still deploys four valves per cylinder. That setup means less mass in the cylinder head and reduced weight for the overall outboard. At the same time, four valves per cylinder means great engine combustion, which contributes to horsepower, torque and fuel efficiency.

Quick Acceleration

The F90 has stepped up to 1.8-liter displacement while dropping 13 pounds. Lighter weight and increased volumetric efficiency, plus increased displacement equals thrilling performance and makes the 90 hp a top performer in acceleration and torque.

Optimal Performance

A TCI microcomputer ignition adjusts timing to maintain optimal engine performance, economy and power under all operating conditions.

Reliability And Durability

Combined with our proprietary alloy (YDC-30), our exclusive Phaze Five™ anti-corrosive paint system provides a tough, five-layer barrier against corrosion. This protection is standard on all Yamaha High Thrust four-stroke engines.