New Yamaha 350 HP V6 Outboard Fills Key Gap in Brand’s Lineup

The 4.3-liter outboard boasts a more displacement, longer stroke and bigger intake and exhaust valves than the Yamaha F300.
Yamaha's new 350 hp outboard
Yamaha’s new 350 hp outboard is powered by a V6 powerhead, which helps keep weight down. Courtesy Yamaha

The new Yamaha F350 is big news for boating anglers. But first, lets it put the debut of this motor into perspective. A few years ago, Yamaha discontinued its 350 hp V-8 outboard, and since then there’s existed an obvious gap between its popular F300 V-6 and the XTO 450 V-8. If you wanted a 350, you had to turn to Honda, Mercury or Suzuki. But all of that changed last week with introduction of the newly designed and much anticipated F350 V-6.

“Boaters asked for it, and we delivered,” said Ben Speciale, president, Yamaha U.S. Marine Business Unit. “The F350 is the perfect big power, light-weight option for a wide variety of applications.”

This 4.3-liter V-6 outboard boasts larger intake and exhaust valves than the F300, and uses the same diameter electronic throttle valve as the XTO 450, according to Yamaha. This is combined with Variable Camshaft Timing (VCT). The intake manifolds offer 40 percent larger surge tanks than the F300, Yamaha says, and the electronic throttle valve is 8 percent larger, all enhancing smoother air flow and power delivery. In addition, a new crankshaft offers a longer stroke, enabling more torque at lower speeds. The compression ratio is 11:1.

The F350 also features Yamaha’s Digital Electric Steering (DES) and Thrust Enhancing Reverse Exhaust for more responsive performance when backing down. Essentially, the exhaust is directed away from the prop to provide clean water so the blades get more purchase for added response.

The Yamaha F350 also incorporates the use of iridium spark plugs for more efficient spark and Yamaha’s new fuel injection control mapping, which produces a longer injector duration than that of the F300 for more power. The F350 incorporates the same water sensor for overheat control as on the XTO 450. A size-up in oil cooler capacity over the F300, along with Yamaha’s sleeveless, plasma-fused cylinder technology reduces friction and enhances heat distribution.

The F350 is offered in 25- and 30-inch shaft lengths, and in 25-, 30- and 35-inch for late-stage customized (LSC) lower unit models. LSC models are equipped with an intermediate drive shaft and shift rod. A new cowling incorporates a water-draining air duct and a new cowling exhaust port combined with a new stator fan to keep everything under the cowling cool.

Used in concert with Helm Master EX boat control system, the F350’s Digital Electric Steering (DES) provides cleaner rigging and extra bilge real estate, according to Yamaha. The F350 also incorporates the same TotalTilt technology used throughout Helm Master EX capable DEC outboards.

The 25-inch shaft version of the F350 weighs 629 pounds; 642 pounds for the 30-inch; and 653 pounds for the 35-inch model. The bigger gear case uses the same propellers as the F300. The new outboard is offered in Yamaha’s Pearlescent White, Traditional Gray, or the new Classic White. The Yamaha F350 will be available in Spring of 2024. To learn more, visit yamahaoutboards.com.

Yamaha 350 hp outboard valve train
The valve train on Yamaha’s new 350 hp outboard benefits from a variety of technological advances. Courtesy Yamaha