2017 Yamaha F300 4.2L Offshore UCA Outboard Motor

This 2017 Yamaha F300 4.2L Offshore, trim code UCA, is a V6 four-stroke outboard built around a narrow 60-degree block with double overhead camshafts and variable camshaft timing. Rated at 300 horsepower at 5500 rpm, it is built for offshore boats that run well beyond sight of the coast.

What it is for

Six independent fuel injectors and a precision multi-point fuel injection system feed the 4.2-liter (254 cubic inch) block, while an In-Bank exhaust and exhaust pressure reduction system are built in for quieter running at speed. A 70-amp alternator sits top-mounted for easy service access.

What to check before buying

• Shaft length: this engine is the U, or 30-inch, shaft version.
• Rotation: an LF counter-rotation model, so confirm it matches your setup for a twin-engine install.
• Fuel: Yamaha recommends regular unleaded with a minimum of 89 octane, filtered through a 10-Micron water-separating filter.

Reliability features

The block uses forged pistons, a water-cooled rectifier and regulator, sacrificial anodes, and a five-step anti-corrosion paint process on the aluminum alloy housing. A TCI microcomputer runs direct ignition, and the Command Link system ties into Yamaha's diagnostic and multi-charge monitoring tools.

What is the compression ratio? 10.3:1.

What is the warranty? Yamaha covers this motor for 3-Year Pleasure, 3-Year Government, and 1-Year Commercial use.

Dry weight on the 30-inch shaft version is 571 pounds (259 kg), and tilt runs to 67 degrees with trim from negative 3 to positive 16 degrees, figures worth checking against your transom and mounting bracket before ordering. Yamaha outboards