The Yamaha V6 Offshore outboards, in the form of the F225, F250, and F300 engines, are topped in the line only by the Yamaha F350 V8 powerplant. But the F350 has been around for over a decade. And through that decade many tweaks and improvements have been made. The result? The Yamaha F350C, with the “C” indicating that this isn’t yesteryear’s outboard engine.

yamaha f350 outboard engines on grady-white
The Yamaha F350 was originally designed to power larger boats than most outboards could handle at the time, like this Grady-White Express 330.

The popularity of the F350 isn’t in question; you’ll find it on everything from single-engine fishboats like the Nautic Star 265 XTS to quad-engine applications like the massive Grady-White 456 Canyon. The engine was designed to provide gobs of torque, swinging a 16.25-inch prop and providing endless oomph with 5.3 liters of displacement. In fact, it’s arguable to say that the F350 provided the impetus for boat-builders to try making larger and larger outboard-powered boats like that big Grady. And as we all know, massive multi-engine center consoles have become all the rage. So, how does the F350C make things even better?

Start with weight. Through the years the Yamaha has trimmed down to the tune of 41 pounds, tipping the scales at 804-pounds upon its introduction and weighing 763 pounds in the “C” form. A change in the exhaust manifold and the expanded use of composite materials is responsible for most of that weight savings.

Next, consider the upgraded ECU. The new brain monitors engine RPM and alerts the owner when service is due. This is particularly important because the engine does have one design issue which can lead to flywheel failure, if it’s run at between 3500 and 4200 rpm for extended periods. This usually isn’t an issue since the average boater cruises at closer to 4500 rpm, but the ECU monitors rpm over the long haul, to make sure problems can be caught prior to any failures. And, just to give its customers peace of mind, Yamaha boosted the warranty from three years for the F350 to five years, for the F350C.

Yamaha also improved the engine’s corrosion-resistance. Since the vast majority of these motors live in saltwater, treatments were developed for metal pieces and parts to boost their longevity. Finally, Yamaha also changed the gearcase to improve the flow of lubricants.yamaha v8 outboard engine

After making improvements to the original platform for over a decade, Yamaha felt the engine was worthy of a new tag: the F350C.

We’ve now run the F350C on dozens if not hundreds of boats, and can happily report that the same smooth, quiet, reliable, smoke-free operation exists with the F350C as it did with the original version. While there are lighter 350 hp outboards on the market, the Yamaha rules when it comes to quiet and inobtrusive operation.

Massive Torque & Power of yamaha banshee 350 hp

  • V8 60-Degree DOHC 32-Valve: The 350’s 5.3: V8 configuration is designed to easily produce 350 prop shaft horsepower, with less stress and strain on internal engine components than small displacement, high-output outboards. Four oversized valves per cylinder increase efficiency and contribute significantly to this engine’s power and torque.
  • Multi-Point Electronic Fuel Injection: Seven different sensors constantly measure vital atmospheric conditions and engine functions to give the Engine Control Module (ECM) the information needed to precisely and instantly adjust the fuel/air mixture for optimum performance and economy.
  • Variable Camshaft Timing: This system advances and retards the angle of the intake camshaft to dramatically increase power and throttle response in the low- to mid-rpm ranges. This gives the engine substantially greater torque between 2000 ~ 3500 RPM to plane large offshore boats with authority.
  • Single Electronic Throttle Control Valve: All air entering the F350 is routed through a single 81mm intake that is controlled by the ECM to ensure the precise amount of air necessary for any given condition. This helps maintain optimum power and efficiency.
  • Dual In-Bank Exhaust with Power Surge Chambers: Yamaha’s exclusive In-Bank exhaust means it exits though the center of the engine between the “V” of the cylinders, rather than on the exterior side, to allow for a more compact shape. The F350 also features dual exhaust with Power Surge Chambers, which help the engine more easily purge the exhaust for greater combustion efficiency and power.
  • Individual Pulse-Tuned Long Intake Tracks: Air enters each cylinder through individual long intake track, which are ‘pulse-tuned’ to provide air at the precise volume and timing for maximum density and power. The result is more low end and mid-range power and torque.
  • Saltwater Series XL™ Propellers: In order to harness the power and torque of Yamaha’s F350, Yamaha designed special Saltwater Series XL propellers specifically to move large, heavy offshore boats. With large diameter and 21% more blade surface area than our Saltwater Series II propellers, they help enable the F350 or deliver up to 45% more thrust than 250hp-class outboards.
  • Enhanced Lower Unit Bearings: An engine with as much power and torque as the F350 needs lower unit bearings and bearing surfaces that stand up to the test. Yamaha has not only changed the type of bearings and/or increased their size, but also hardened the surfaces on which they ride, for increased reliability.

Specific Offshore Design of yamaha banshee 350 hp

  • Variable Trolling RPM Control: By just pressing a button on the Command Link gauges, the operator can adjust the engine’s trolling speed from 600 ~ 1000 rpm, in 50-rpm increments. This helps provide precise and consistent trolling speeds in a wide array of conditions.
  • Enhanced Cowling Drain System: The F350 features a new cowling drain system, to easily and efficiently drain away water that enters the cowling during normal engine operation. Incoming air is routed through a labyrinth of passages that trap and drain water before it enters the engine’s intake, for enhanced reliability.
  • Ultra-Tough Gear Case: Completely new, it’s large, streamlined design incorporated hardened gears and high strength oversized bearings and bearing surfaces to handle the tremendous power of the F350.
  • Adjustable Maximum Tilt Angle: Due to the myriad of hull designs to which the F350 applies, it features and adjustable maximum tilt angle. With a simple programming change through the Yamaha Diagnostic System, it’s possible to adjust the full tilt-up setting on the F350 to meet the requirements of individual application.
  • Forged Motor Mounts with Oversized Mounting Bracket: The F350 features four motor mounts made of strong forged aluminum, which means they’re compressed in molds for much greater strength than cast aluminum-type mounts. The oversized mounting bracket features the same bolt pattern and centerline as the F250, but uses two additional mounting bolts for a total of six. It is designed to handle the engine’s power while minimizing noise and vibration.
  • Dual Water Inlets: The F350 comes standard with dual water inlets, for maximum cooling capacity. Located on the front and sides of the lower unit, each pair of pick-ups operate independently of one other to ensure proper water flow in a wide variety of applications and conditions.
  • Tri-Seal Smooth Latch System: Yamaha has improved its Tri-Seal system to ensure a better fit and seal between the cowling and the lower pan. This means increased resistance to water intrusion for even greater levels of reliability.
  • Dual Labyrinth Exhaust: Every Yamaha F350 features a Dual Labyrinth Exhaust system that routes the engine’s exhaust through not one, but two mazes before it exits above the waterline in dual idle relief outlets, for smooth, quiet operation.

A New Level Of yamaha banshee 350 hp

  • Command Link® Digital Electronic Control System: Yamaha’s new Command Link Digital Electronic Control systems feature built-in redundancy in critical areas for added reliability.
  • Direct “Coil-In-Cap” Ignition: The F350’s advanced engineering features spark plug caps with the ignition coils built right in. The result is increased performance and reliability in a much simpler and more compact design.
  • Ionic Combustion Sensors: Individual sensors constantly monitor the condition of combustion in each cylinder for incomplete combustion and, should this occur, they immediately signal the ECM to adjust spark timing to correct it.
  • Insulated Fuel Feed Pump: The electric fuel feed pump on the F350 is located in the lower pan, away from the engine’s heat, and encased in an insulated enclosure to help prevent troublesome issues such as vapor lock.
  • Anodized and Coated Forged Pistons: The F350 uses eight forged pistons, which are formed under pressure for maximum strength. The pistons are also anodized for corrosion protection and coated with a layer of solid lubricant for added reliability.
  • UPC-II™ Ultimate Corrosion Protection System: Yamaha improved their corrosion protection system for the F350. Yamaha’s proprietary alloys, ACP-221 paint process, and freshwater flush device are just the start. Add to that multiple additional sacrificial anodes in and on the power head, mid-section, and lower unit; enhanced head gaskets, a special power head paint process that coats both the entire outside and the inside passages of the block, and an anodized exhaust system, and you’ve got Yamaha’s most advanced corrosion protection package.
  • Dimpled Cylinder Sleeves: The F350’s outer cylinder sleeves feature a “dimpled” surface. This helps maintain the roundness of the cylinder for decreased oil consumption, and increase the cooling surface area of each cylinder for added reliability.
  • Large Capacity Oil Pan: Oil is the life-blood of any engine. Designed not only to lubricate, but carry away heat and combustion by-products. It’s essential to have an ample supply on hand. At just over 8 quarts, the F350 does.
  • The Yamaha F350 was introduced as a locomotive of an outboard, a torque-monster 5.3-liter V8 swinging a 16.25-inch diameter prop with the authority required to push the 11,000-pound 11’ 7” wide Grady-White Express 330 up onto plane or over a barn-high swell. A pair of F350 motors was portrayed as a light-weight, space-saving alternative to inboard engines on boats that were simply too heavy for any other outboard engines available at the time. With F350 outboards on the transom, there was suddenly a big empty space where an engine room used to be–room for fish boxes or an aft cabin.

    In the ensuing decade applications for the F350 have broadened; a single V8 Yamaha is replacing twin 200 HP motors on many center console boats, for example, and even powering mega-pontoons. And the population of larger outboard-powered boats has grown significantly, according to Yamaha, which reports that sales of boats over 35 feet have increased 31 percent since 2007.

    yamaha banshee 350 hp

    The Mercury Verado 350 can match the horsepower rating of the F350C, but only the exotic 6.2-liter V8 Seven Marine 557/627 can top the displacement of the big Yamaha in the outboard category. Yamaha stresses that its normally-aspirated V8, aided by variable intake valve timing, produces exactly the torque curve ideal for pushing a heavy boat–rising smoothly and quickly off idle and staying fat in the mid-range. It’s that power that gets translated into thrust through a prop with lots of blade area. Mercury can squeeze up to 400 HP from its Verado platform, but relies on a supercharger to blow power into a 2.6-liter six-cylinder powerhead and a 5800 to 6400 WOT RPM range to produce peak horsepower. It’s worth noting that the Verado platform was originally designed to produce at most 275 HP. It’s also worth noting that a Verado can swing a 16-inch diameter prop, and I have never been disappointed in the supercharged thrust produced by a Verado, even on a heavy boat like the Boston Whaler 370 Outrage, which we ran with a Verado 350.

  • Yamaha claims the F350 is the better tool for the job of moving a heavy boat, and it’s been honing that tool over the years. The changes to the gearcase entailed revising internal passages to provide a better pathway for lubricant to gears and bearings, which are under a lot of load in this motor. Corrosion resistance was improved below the waterline when the motor is at rest, through the use of improved metal treatments. The F350C weighs 763 pounds, or about 41 pounds less than the original, 804-pound F350 (but still almost 100 pounds more than a 668-pound Verado 350). Much of that weight reduction is due to a revised exhaust manifold, but Yamaha has also shaved ounces here and there through the use of composites and the redesign of other components. That weight reduction may not affect performance or economy at all on big boats, but it can’t hurt.

    The F350C is fitted with an ECU (Engine Control Unit) that monitors time of use in specific RPM bands and then gives the owner an alert when regularly-scheduled service is due. The ECU specifically clocks the time the motor spends between 3500 and 4200 RPM to address an issue with the flywheel design of the F350. A few years after the F350 was introduced it was discovered that a “harmonic event” takes place within the engine between 3500 and 4200 RPM that over time could cause the flywheel to fracture, leading to major engine damage. With no apparent fix for this issue short of redesigning the engine, Yamaha has a policy of simply replacing the flywheel after the engine has run for 80 hours within that 3500-to-4200 window, and set up the new ECU to count those hours. Note that this interval is not for 80 total hours of operation, rather only the hours in that RPM range, which is likely below the best cruising range for most boats. The performance of each boat will determine how much time the motor spends in this state of harmonic dissonance. This ECU has been retrofitted to earlier F350 models at no charge for a few years, and Yamaha also picks up the cost of replacing the flywheel. Perhaps to boost consumer confidence, Yamaha has also extended the base warranty of the F350C from three years to five years, with an additional two years of coverage available at extra cost.

    We recently sampled the F350C in Baltimore Harbor on a Shearwater 26 Carolina, a delightful 25’ 8” center console that weighed about 5,000 pounds with power and fuel. The power of the F350C came on smooth and deliberate, lifting us smartly out of the hole. But then the big V8 showed some legs, pushing the Shearwater to a top speed of 60.8 MPH while swinging a Turbo Offshore 14.25 x 19 prop. Best fuel economy was also impressive–2.59 MPG at 4000 RPM and 37.5 MPH. The smooth, quite operation of this motor is always impressive, and it’s essentially silent at trolling speed.

Standard Features of yamaha banshee 350 hp

  • Engine Sensing Warning System
  • Engine Stop Switch Lanyard
  • 3 Year Limited Warranty
  • Enhanced Ultimate Corrosion Protection System (UCP-ll™)
  • Electronic Fuel Injection
  • External Tilt Switch
  • High Output Alternator
  • Micro-Computer Ignition System
  • Multi-Charge Monitoring System
  • Power Trim and Tilt
  • Sure-Seal Tri Latch
  • Thermostatic Cooling System
  • Remote Steering
  • Freshwater Flush
Optional Equipment