All the 250hp outboard engines compared

If you own a big trailer boat, you are going to need some high horsepower to push it around.

One of the sweet spots in the higher-performance outboard engine line-up is the 250hp category.

It’s an engine class dominated by V6 engines, but there is also a big-block V8 in the mix for those who still believe there is no substitute for displacement when it comes to running offshore.

These days, outboard engines are all very safe, reliable, durable and user-friendly. 

Huge advances in technology made in recent years are reflected in the improvements in power-to-weight ratios for these engines pretty much across the board and in the increased torque and low-down power delivery of the four-stroke outboard engines in particular.

Here are your options if you’re in the market for a new 250hp outboard engine.

Honda’s 250hp 3.6-litre V6 outboard engine is based on a road-going powerplant originally developed for the Honda Odyssey passenger vehicle.

This engine is the only one here to feature a single overhead cam design – important for helping an engine eke out performance when it counts, and better fuel economy. Of note, Honda has developed a new-generation 3.5-litre V6 featuring twin-cam technology that may one day be adapted by its marine division.

This outboard engine is also the highest in performance that Honda has developed.

To help give the engine a low-speed torque boost, Honda has developed something called ‘boosted low-speed torque’, or ‘BLAST’. The engine electronically adjusts the air-to-fuel ratio and ignition timing at low revs to increase the amount of torque generated, and at higher revs the VTEC valve timing adjusts to help improve power and limit fuel use.

The engine’s full throttle operating range is from 5300rpm to 6300rpm, showing it is not afraid to pile on the revs to extract performance. The engine will also produce 90A of power at running speeds.

Honda has a drive-by-wire shift and throttle control system that can control up to four engines, while its mechanical control system can support up to two engines. Honda does provide a trolling mode for the BF250, but only if the engine is controlled digitally.

The engine’s 286kg dry weight makes it the heaviest of the 250hp options on the Australian market. On the plus side, though, Honda claims its BF250 is the quietest in its class and the most fuel-efficient.

Honda offers its ‘iST’ intelligent shift and throttle digital control system for the 250hp engine.

Of note, the circa $30,000 Honda offers a best-in-class seven-year warranty for its outboard engines comprising three years of factory warranty and another four years of extended warranty provided you take it to an authorised Honda service centre for its annual/100-hour maintenance schedule.

Honda does not offer a joystick control system with its outboard engines, although it has built them to be compatible with Dometic’s Optimus 360 system.

The engine is available in 508mm (20-inch), 635mm (25-inch) and 762mm (30-inch) shaft lengths.

US outboard engine specialist Mercury has four versions of its 250hp outboard engine available for buyers.

All are based around a narrow-bank 4.6-litre V8 equipped with dual overhead cams and electronic fuel injection. The slightly wider bore compared with the engine’s stroke length – the engine is classed as oversquare – makes it good at producing more torque at low revs.

There are subtle differences between each of the engines, ranging from shaft lengths to final drive ratios, and in the case of the Verado version, how they attach to the boat and how much recharging power they turn out.

The most basic 250hp engine is the 250 FourStroke, which produces its power from 5200-6000rpm on unleaded fuel. It weighs 239kg and is priced at around $35,000.

A step up the performance chain is the circa $38,000 250hp Pro XS, an outboard engine that uses a taller geared lower section called Torque Master to produce more top-end speed. Helping things is a higher operating limit that lifts to 5600-6200rpm. It is also slightly lighter than the base FourStroke, weighing in at 229kg, a 10kg saving.

For anyone wanting a long-lived commercial outboard engine, the choice is the circa $37,000 250hp SeaPro. It limits its revs to a maximum of between 4800-5600rpm to ensure it has an easier working life than a boat used recreationally. It weighs in the same as the 250hp FourStroke on which it is based.

All these engines use an 85A alternator and a choice of either traditional or fly-by-wire steering and throttle controls. While the 250 FourStroke and 250 SeaPro all come in 508mm (20-inch), 635mm (25-inch) and 762mm (30-inch) shaft lengths, the Pro XS will only come in 508mm and 635mm (5.44:1) lengths.

At the pinnacle of Mercury’s 250hp range is the 250 Verado, which can cost around $45,000 depending on the configuration and colour. It operates in the same rev range as the FourStroke but uses Mercury’s Advanced Mid Section to connect to the boat’s transom. This mount is better at isolating noise and vibration than the more traditional engine mount, with the only drawback being that as a consequence, this engine weighs 272kg.

The 250hp Mercury Verado uses a larger alternator that lifts the amount of charging power the engine generates to a more house battery-friendly 115A.

While the Pro XS and SeaPro engines are only available in black, the 250hp FourStroke and Verado engines can come either in black or three shades of white, but with an infinite number of coloured highlights available.

All engines use Mercury’s SmartCraft Engine Guardian system that monitors a system of sensors located around the engine to feed real-time information back to one of Mercury’s four console-mounted VesselView touchscreen options.

Mercury offers a six-year warranty on its engines, with three years of factory-backed warranty extending to six years if the outboard is serviced at an authorised Mercury dealership.

You can fit most of these engines with a digital shift and throttle system replacing the default cable one. The engines also come with a tilt-limiting system that stops them from hitting engine wells and bait boards, keyless start and low-speed trolling modes. Mercury also features a docking system on its digital shift and throttle control that can dull the throttle and limit the revs when coming alongside a dock.

The engines are all also compatible with Mercury’s Joystick Control system which allows users to precisely control a boat fitted with multiple engines. Mercury does not offer joystick control for single-engine applications.  

Suzuki’s 250hp outboard engine is unique in that it is based on a narrow-banked 55-degree V6 block that displaces only 3.6 litres. The under-square block is shared with Suzuki’s DF225 and F200 outboard engines, with the DF250 being its most powerful version.

Prices for the Suzuki DF250AP start from around $34,000.

Most V6 engines use a 60-degree bank, but Suzuki uses a 55-degree angle. This allows Suzuki to create a more compact outboard engine package. 

Suzuki also stands out in that it uses an offset drive shaft to move the engine’s mass more inboard, as well as a two-stage reduction gearbox to allow the engine to use an industry-low 2.29:1 ratio. The low ratio allows Suzuki to spin a larger three-blade propeller, up to 27.5 inches in pitch, giving the engine more bite on the water and improving acceleration.

The engine is also built with a self-adjusting timing chain to increase the engine’s durability and uses two water pick-up sources to cool the engine – handy if one becomes blocked by weed or debris. 

The Suzuki DF250AP comes in long (508mm), extra-long (635mm) and extra-extra-long (762mm) shaft lengths to help with different mounting options and multi-engine applications.

The Suzuki DF250AP’s alternator will put out a maximum of 54A, and the full throttle range is between 5500rpm and 6100rpm.

At 264kg in its lightest form, it’s far from the lightest option here.

Suzuki’s Precision Control digital throttle and shift system can replace a mechanical cable system, as well as allow multiple engines to be controlled via a single lever.

Another big benefit is automatic trim, available via the SMG4 multifunction engine gauge interface.

Suzuki does not offer keyless start for the DF250AP, although it does use a smart system that lets the operator start the engine without holding the key on.

Suzuki offers a six-year warranty on its 250hp outboard engine comprising three years of factory warranty and another three years if you have your engine maintained at an authorised service centre. 

Yamaha last tweaked its V6 Offshore high-performance outboard engine line-up in 2021, with the circa $35,000 Yamaha F250 gaining a host of upgrades.

The most notable was the addition of ‘DES’, Yamaha’s bolt-on digital electric steering, which opened up the F250 to a host of new features including compatibility with Yamaha’s Helm Master EX joystick control system for single and multiple engine installations, and autopilot.

The Yamaha F250 is based on a 60-degree 4.2-litre twin-cam V6 engine shared with the 225hp and 300hp versions. It runs at a lower maximum rev range than rivals, between 5000rpm and 6000rpm, but with a square bore versus stroke ratio and a 2.0:1 gear ratio.

Of note, Yamaha trimmed weight off the F250 by removing the steel cylinder sleeves from the block and instead using a plasma fusion process to harden the cylinder walls. It means the F250 tips the scales at a minimum 263kg.

One of the clever things that Yamaha introduced with the tweaks was diverting the through-propeller exhaust system so that it exits above the anti-ventilation plate and doesn’t interfere with the engine while it is in reverse – mixing the exhaust with water causing the prop to slip badly.

Yamaha has also beefed up the engine’s lower unit to help with durability. 

A handy function is that the engine will now automatically tilt as soon as the skipper double-taps the trim toggle switch. The height it rises can be limited so it will never do a full tilt if needed.

Yamaha has also made it easier to take care of the engines once the trip is over, offering an optional onboard engine flushing system that routes through the rigging tube.

The F250’s alternator will produce 70A of recharging power, while the drive leg runs a 1.75:1 gear ratio. 

Yamaha also produces the Yamaha VF250 Vmax SHO, based on the same 4.2-litre engine and with the ‘SHO’ standing for ‘super high output’.

The VF250 has a sportier-looking cowling as well as a unique lower drive unit using the same 1.75:1 gear ratio as the more recreationally focused version. It produces only 50A of charging power.

This engine is not compatible with Yamaha’s digital throttle and shift controls, instead relying upon mechanical rigging.

The Yamaha F250/F250 DES is available in 643mm extra-long and 767mm ultra-long shaft lengths, while the VF250 is available in 493mm long and 643mm extra-long shaft lengths.

Yamaha offers a four-year warranty on its outboard engine range — the shortest of all the manufacturers here — comprising two years of factory warranty and two years of extended warranty if you stick with using an authorised service centre for maintenance.

Tohatsu sells a rebranded Honda BF250 outboard engine under its own name and featuring a different cowling than the Honda donor.

The engine is only available in an extra-long 635mm shaft length.