News Stories

Yamaha’s New 350-Horsepower 4.3-Liter Outboard

Yamaha, F300, Outboard Engines, News Release

On Wednesday Yamaha’s introduced its newly-designed F350, filling a hole in the company’s lineup that has existed for several years. The company says engine block and gearcase upgrades give the new outboard a strong core for powering up and going the distance, while comfort and convenience options create a user-friendly system. 

New F350 Offshore

The F350 4.3-liter V6 outboard boasts larger intake and exhaust valves than the F300 and uses the same diameter electronic throttle valve as the 5.6L V8 XTO® 450 to maximize air movement.

Yamaha, News Release, Outboard Engines, f350

Multiple engineering improvements add power and ease of use to the 2024 Yamaha 350 V6.

Better air flow equals more power as the F350’s precisely mapped fuel and ignition timing match operator throttle demand for responsive performance, according to the company. A new crankshaft offers a longer stroke and a slightly higher compression ration than the F300, at 11:1. This change should enable more torque at lower speeds. The outboard also includes Yamaha’s Digital Electric Steering (DES) and exclusive Thrust Enhancing Reverse Exhaust.

With a 11:1 compression ratio, the new F350 manages air displacement using tailored intake manifolds equipped with 40 percent larger surge tanks, as compared to the F300. Identical port and starboard intake manifolds enable the ideal placement for the 81mm electronic throttle valve that is 8 percent larger than the F300 throttle valve and center-mounted for smooth air flow and responsive power, per the company.

Yamaha, News Release, Outboard Engines, f350

The new Yamaha 350 outboard features an improved fuel system with larger intake and exhaust valves among other advances.

Yamaha also says larger intake and exhaust valves and Variable Camshaft Timing (VCT) offer air flow advantage for the new F350. It also incorporates the use of iridium spark plugs—appreciated for their hardiness and concentrated, efficient spark—combined with Yamaha’s new fuel injection control mapping, which produces a longer injector duration than that of the F300 4.2L for more power.

For durability, the new Yamaha F350 incorporates the same water sensor for overheat control used on the XTO 450, which helps catch increasing engine temps sooner than traditional sensors by monitoring the temperature of the cooling water, not the block. A size-up in oil cooler capacity over the F300, along with Yamaha’s sleeveless, plasma-fused cylinder technology for exceptional strength, reduce friction and create precise heat distribution.

More Improvements

The vigorous foundational propulsion of the new gearcase is merged with Yamaha’s Thrust Enhancing Reverse Exhaust (TERE) technology, which keeps exhaust bubbles above the anti-ventilation plate and away from the propeller at 2500 RPM in reverse to produce high thrust when backing down on a fish and to add more precision when maneuvering around the docks.

The F350 is offered in full model 25-inch or 30-inch shaft lengths and 25-inch, 30-inch and 35-inch for late-stage customized (LSC) lower unit models. LSC models are equipped with an intermediate drive shaft and shift rod.

Yamaha, News Release, Outboard Engines, f350

An improved cooling system creates more available current for the electrical system, per Yamaha engineers.

The new F350 cowling incorporates the best in Yamaha offshore motor advancements with its water-draining air duct, while the new cowling exhaust port combined with the new stator fan keeps everything under the cowling cooler. The cooling effect is impactful enough to create more available current for the new F350 over the F300 at all RPMS, especially in the lower RPM ranges.

Used in concert with Helm Master EX boat control system, Digital Electric Steering (DES) provides clean rigging and extra bilge real estate that offers smooth, responsive steering and easy maintenance. Mirroring smart functionality on the XTO, the F350 has a convenient, flush connection running through a specially designed rigging grommet inside the rigging tube that can be connected to an automatic flushing system.

Manual flush is also possible with a separate flushing connection. The F350 also incorporates the same TotalTilt® technology used throughout Helm Master EX capable DEC outboards.

Now offered in Pearlescent White, Traditional Gray, or new Classic White the new Yamaha F350 will be available in Spring of 2024.

New Helm Master EX Features

Helm Master EX with integrated bow thruster control is now available for single through quint applications. Yamaha’s integration of Sleipner® and VETUS® bow thruster systems is an on-demand, self-activating feature. It works congruently with the Helm Master EX joystick to enhance lateral movement and pivoting by automatically engaging the bow thruster in variable speed to match operator input. The bow thruster also automatically supports Setpoint functions (Staypoint®, Fishpoint®, DriftPoint® and DriftPoint track) and can help keep the boat on track when using autopilot functions.

Yamaha’s integrated variable speed bow thruster is only available through boat builder installation on new boats. The integrated bow thruster control is available now for twin and triple applications. Anticipated availability for single, quad and quint applications is spring, 2024.

New Pitch Options for the Saltwater Series II Propeller Line Yamaha brings new pitch additions to the reliable Saltwater Series II propeller. Known for awesome performance and fuel economy, the line now works for a wider variety of boat applications. The introduction of right- and left-hand rotation 14-inch, 24-inch, 25-inch pitches, and a 16-inch pitch left-hand model, round out the Saltwater Series II product line, ensuring this popular propeller is offered in one-inch increments from 13-inch to 25-inch in both standard and counter-rotation.

Yamaha Saltwater Series II propellers are made using highly polished 15-5 stainless steel, which provides extra strength for moving large volumes of water, a longer cruising range and better handling in rough seas, per the company.

The new Saltwater Series II pitches will be available in Spring 2024.