Honda BF350 outboard engine 2024 Review

Honda Marine was the first of the major outboard engine makers to adopt four-stroke outboard engines exclusively, but in recent times this relatively conservative Japanese company has trailed rivals when it comes to bringing new or updated outboard engines to market.

However, when Honda does introduce a new outboard engine, most knowing people in the marine world stand up and take notice because you can count on it being something pretty special.

These thoughts were front of my mind during the recent launch on the Gold Coast of the Honda BF350 at a media and dealer event timed to coincide with the start of the 2024 Sanctuary Cove International Boat Show.

The all-new 5.0-litre V8 Honda outboard engine was made available for testing on the Gold Coast Broadwater with single BF350s mounted on a Parker 920 Explorer and a Lilybaeum Levanzo 25, and with a pair of them powering a Robalo 317 dual console.

In the 350hp outboard engine class, the four main protagonists have gone in different directions.

Yamaha has gone to a V6 from its previous, and dated, V8. Mercury has opted for a large-capacity V10, and Suzuki has a narrow-bank V6 engine paired with a drive system that runs a pair of counter-rotating propellers.

With its new BF350, Honda Marine has opted for something different again, in the form of a 60-degree V8 with a capacity of 4952cc.

Honda’s renowned Variable Timing and Lift Electronic Control (VTEC) is also used in the BF350 to enhance power and performance throughout the rev range.

VTEC changes the camshaft profile to deliver a broader, flatter torque curve for a smoother, more consistent delivery of power high up in the rev range.

The Honda BF350 is also equipped with Honda’s BLAST (Boosted Low Speed Torque) feature that advances ignition timing when you gun the throttle to boost torque for quicker acceleration and fast holeshots.

Helping with fuel efficiency is Honda’s Lean Burn Control Technology which automatically optimises the air/fuel mixture according to engine revs, engine load and boat speed.  

An O sensor mounted in the exhaust passage of the right-hand cylinder head is also used to monitor air/fuel ratios by measuring the residual oxygen content of the exhaust gases.

To further improve fuel efficiency, the BF350 employs an “advanced plateau honing process” whereby the cylinder walls are machined to a finish smooth enough to retain oil and thereby reduce piston friction.

For the ultimate in smooth, vibration-free operation and to pack the engine more compactly for multi-engine installs, the BF350 has a fully balanced 60-degree offset crankshaft that eliminates the need for counterbalancing.

Honda says the offset crankshaft “seamlessly integrates with the 60-degree engine design and non-linear engine mount to provide exceptional performance with minimal vibration”.

The crankshaft is also forged using the same high-strength metals used in the V6 engine that powers Honda’s renowned NSX sports car.

With regard to engine weight, the BF350 is slightly heavier than its rival 350hp outboard engines at 347kg for the lightest model.

By comparison, the lightest of the 350hp outboard engines is the Yamaha F350 at just 250kg. The Mercury V10 350hp is next best at 316kg, with the Suzuki weighing 330kg.

The new engine also comes with a screen that mimics the dashboard of the Honda NSX supercar, but this was not uploaded to our test boats. Instead, our test boats all used the Honda HD-5 displays.

Visually, the BF350 presents as a tall, slim, attractive and futuristic-looking engine.

The BF350’s narrow profile allows for 28.5-inch (724mm) mounting centres to make it ideal for twin, triple and quad outboard engine installations on everything from commercial RIBs through to offshore fishing centre consoles.

Viewed from each side the BF350 has quite an imposing presence, but in a good way.

The one-piece cowl is large, but pleasingly lightweight – it weighs the same as a 250hp engine's cowl – and easy to remove for servicing and maintenance.

The big V8 Honda is available in two colours; Honda’s classic Aquamarine silver metallic along with Grand Prix White as tested.

The BF350 is available in two standard sizes, extra-longshaft 635 (25-inch) and ultra-longshaft 762mm (305-inch) configurations.  

Pricing for these big V8 Hondas has yet to be formalised, but Honda has advised that the engine itself should come in below $50,000. With basic rigging the price should rise to around $54,000.

As you might expect from a new, high-tech outboard, the BF350 has plenty of user-friendly features.

For example, to provide more electrical power when needed, the BF350 has a system whereby the engine speed will automatically advance by 100rpm to produce an extra 13 amps to run multiple accessories.

At idle the standard 30-amp alternator output is boosted to a maximum of 43 amps.

The maximum alternator output is 70 amps at 6000rpm.

The BF350 will run happily on our regular unleaded petrol (86 octane overseas), saving cost at the pump.

It also comes with a new binnacle throttle controller with a five-button multifunction panel for control of engine functions including cruise control, troll mode, an electric tilt-limit (to stop over-tilting and potentially damaging the engine cowl), and trim support.

With the latter, there are three customisable presets to automatically trim the engine so that your boat will plane quickly whilst also optimising fuel economy.

Other cool features include NMEA 2000 compatibility (for running third-party onboard systems and multifunction displays without the need for a manufacturer's interface); Honda’s intelligent shift and throttle (iST) drive-by-wire system for effortless throttle control; plug-and-play compatibility with the optional Dometic Optimus 360 joystick control system; improved corrosion resistance; multiple engine system alerts/alarms; a freshwater flushing port; and single-throttle lever operation convenience on multiple engine installations.

Service intervals for the Honda BF350 are similar to others in its class. After an initial 20-hour service for checks and minor adjustments, the service schedule runs annually or every 100 operating hours.

The Honda BF350 is well suited to powering a mix of boats in single and multiple-engine installations.

We sampled this mighty new engine on the back of three different boats. The first was a single-engine install on a moderate-weight Parker 920 Explorer cabin cruiser.

The second boat was a chic Italian-made, highly-styled dayboat centre console called the Lilybaeum Levanzo 25.

The smaller Lilybaeum was also paired with a single Honda BF350, making it interesting to compare it against the Parker cruiser.

Rounding out the trio of Honda BF350-powered test boats was the new Robalo 317 DC with two Honda BF350s bolted to the broad transom.

It is often easier to get a feel for the performance of an outboard engine when it is mounted as a single. However, with the two BF350s mounted on the Robalo, the test rig planed on just one of the two engines to demonstrate the BF350's low-down torque.

With one engine switched off and tilted up, the remaining BF350 lifted the big Robalo onto the plane quite easily, accelerating to a comfortable cruise speed.

With regard to the single-engine boats, I found the performance characteristics to be quite similar despite the size and weight difference between them.

I would judge the smaller, lighter Lilybaeum to be the quicker of the two boats to plane and accelerate through the rev range. However, these big Hondas have such a broad spread of power and torque that the delivery of this power comes on in sweeping waves rather than with an instant hit. This allows the Honda to power light and heavier-weight boats equally well – correctly propped, of course.

The lighter-weight Lilybaeum was ultimately the slightly quicker of the two, tapping out at a rip-snorting 46.0 knots.

The larger Parker 920 Explorer was no slouch though, achieving a top speed of 43.0 knots at 5700rpm with a fuel burn of 124L/h.

Unfortunately, we were short of time at the Honda media launch and were not able to conduct our usual full-performance trials.

In other respects, the Honda BF350 also excels. Each of the test engines started instantly, before settling into a smooth, purring idle speed. There was no vibration and very little noise.

V8 enthusiasts might be disappointed by the lack of a characteristic engine note, but I rather suspect a loud rumble would get tiresome after a while.

Underway, the Honda BF350 is also smooth and quiet at cruise speeds to around 4500rpm; you can easily carry on a conversation at the helm.

Noise levels do escalate beyond 5000rpm, but that is to be expected, and I would guess it to be similar to rival makes. However, the engine does have a noticeable, snarly change in pitch when the VTEC cam change kicks in under load from 4800rpm.

The BF350 is the first new outboard engine that Honda Marine has released in a number of years, and it’s a ripper.

This ultra-cool looking V8 delivers a powerhouse of performance to power everything from lightweight sports day boats to family cabin cruisers, sports RIBs and multiple-outboard fishing centre consoles.

This big engine is smooth, quiet, powerful and loaded with a suite of user-friendly features and enough high-tech wizardry to make it more than a match for its rivals.

Specifications:
Model: Honda BF350
Engine type: Four-stroke SOHC 32-valve
Cylinders: 60 degree V8
Fuel management: EFI
Weight: 347kg (lightest model)
Displacement: 4952cc
Bore x stroke: 89mm x 99.5mm
Maximum output: 350hp @ 5500rpm
Operating range: 5000rpm to 6000rpm
Shaft length: 635mm (25-inch), 762mm (30-inch)
Alternator: 12V/70A
Trim method: Power trim/tilt
Gear ratio: 1.79:1
Recommended fuel: Regular unleaded
Counter-rotating: Available
Servicing: Annually (or every 100hours after first service)
Emissions rating: CARB 3-star/OEDA 3-star
Warranty: 5 + 2 years (when serviced at a Honda dealer), 3 years commercial.

Priced from: About $54,000 for the extra-longshaft 635mm (25-inch) model with basic rigging, propeller and installation.

Supplied by: Honda Marine Australia