The Future Of Outboards

OUTBOARD engines will remain reliant on petrol for at least the next two decades, meaning fishos will have to use their boats more effectively to minimise fuel costs and maximise time on the water.

Even though outboard companies are actively investigating alternative fuels to power recreational boats, the release of any new technology is many years off, Fishing World has discovered.

The short to medium-term focus by the big outboard companies will be on developing fuel efficiency across existing platforms rather than introducing alternative power systems.

In the meantime, boat fishos can employ a variety of tactics to minimise how much juice we use during a day on the water. Outboard experts interviewed by Fisho all say that getting rid of your smelly, noisy and thirsty old two-stroke Carbi is probably the best way to reduce your fuel bills, especially if you’re an offshore fisherman or do lots of miles at medium to high speed.


The new age DI two-stroke and EFI four-stroke outboards are far more fuel efficient than traditional two-strokes, as well as being significantly more environmentally friendly. Gregoire Dupont, from Evinrude E-TEC, says new technology engines offer fuel savings of up to 50% in an ICOMIA duty cycle over “dirty” old two-stroke donks.

But you need to fully assess the benefits of changing engines before you lash out. If you run a standard two-stroke tiller steer outboard of less than 25hp, you’ll need to do a hell of a lot of fishing and burn a lot of fuel to recoup the extra money needed to invest in a four-stroke or DI two-stroke.

For example, if you used your small two-stroke outboard for 100 hours a year with an average fuel use of 10 litres an hour you’d go through 1000 litres. At an average of $1.60, that’s $1600 on fuel for your estuary or river fishing (plus a bit extra for two-stroke oil 25 litres at 40 AUD a litre 1000 AUD and E-TEC would use 6 litres to put it in prespective, at current price of 50 AUD a litre 300 AUD a little cheaper than the 20 hour and first service on the fourstroke (400 AUD), the sump on a 25 fourstroke will carry around 4/5 I think).

If you purchased an equivalent horsepower four-stroke or DI two-stroke, you’d have an engine that was far quieter, more enviro-friendly, economical, technologically advanced and in general a much more pleasant to use, a better fishing tool (no noise, fewer rattles/vibration etc) which would cost about $1000 a year in juice (and extra for the oil used in the DI two-stroke would leave this out as you will need to change the engine oil on the fourstroke overall labour and oil cost amounts to even more cost than the two stroke).


You’d have to run this new engine for 100 hours a year for at least three years to earn back the higher initial purchase price, based on a new technology 25hp outboard being about $2500 (1800 AUD) more a two-stroke model.

Is it worth it? That’s a personal choice. On purely economic grounds, it probably doesn’t make sense, as only the keenest and most dedicated anglers would run a small boat for 100+ hours a year and thus recoup the costs on fuel use savings. But the environmental and ease of use benefits of the modern engines are compelling, and when combined with fuel savings – noting that $1.60 is a fairly conservative estimate – make the choice somewhat easier to make.

Ensuring your boat is rigged up with the correct prop will also see fuel savings of up to 20-30 per cent. That doesn’t sound all that much but if you fish the shelf every weekend over the summer gamefishing season, it definitely adds up. Say you fish 20 weekends and use 150 litres of fuel each time out with a well-maintained 150hp two-stroke fitted with a run-of-the-mill prop. That use equals 3000 litres of fuel used, which at an average of $1.60 a litre is $4800. If you fit your boat with a more effective propeller you could save up to $1200, based on a 25 per cent increase in efficiency, which will give you another 750 litres of fuel and another five weekends on the water (bearing in mind, of course, that quality SS props aren’t cheap!). And if you swapped your fuel-intensive two-stroke for a DI two-stroke or four-stroke, you’d get probably another grand in fuel savings and even more time on the water!
Click here for a really nifty prop selector website from Mercury to assess which prop is best for your boat.

As a general rule of thumb, however, the engine should reach the maximum rev range with the correct prop. So if your engine is designed to rev out at 5800, and you only get to 5000, you probably need to look at getting another prop with 2 or 3 inches less pitch.

Once you have the engine and prop sorted, then you have to consider oil use and servicing. Four-strokes are more expensive to service than DI two-strokes (Evinrude’s DI E-TEC requires much less scheduled servicing than other engines) but the modern two-strokes like Mercury’s Optimax, Yamaha’s HPDI and the E-TEC use expensive oil, which is automatically mixed with the fuel, albeit it often in miniscule amounts. You’ll have to do the sums yourself to work out which type of engine is cheaper to run! Based on Fisho’s experience, it works out to be six of one and half a dozen of the other.

While the car industry has by necessity embraced hybrid and other technologies to offer consumers more choice in reducing fuel use, fishos need to realise the marine sector is limited in the sort of changes it can offer. The global outboard market is too small to allow manufacturers to recoup the vast amounts of R&D expenditure required to develop any marketable alternative to petrol powered outboards. And many of the new systems being implemented by the car industry just aren’t suitable for marine use.

While various car companies have adopted hybrid motors, marine industry pundits say the batteries needed to power these new generation engines are too heavy and too susceptible to damage from saltwater to be considered feasible. Other potential fuels such as hydrogen, diesel and LNG pose problems with R&D costs, power to weight ratios and accessibility.

“Any significant change to alternative fuels is a long way off,” Evinrude’s Gregoire Dupont told Fisho. Like most of the outboard companies, Evinrude’s parent company BRP is setting up an R&D facility to investigate new fuels. This facility will be based in Europe and Dupont doesn’t expect any breakthroughs for at least 10 to 20 years.

That’s not to say that there aren’t any alternatives available now. Mercury’s outboard guru Ken Evans says advancements have been made with LPG powered outboards – this relatively cheap and abundant fuel delivers about 20 per cent less power than petrol and has become more attractive as an alternative as petrol prices have risen. “The need for gas cylinders, lack of LPG outlets and government restrictions means that any introduction of LPG-powered outboards will be very complicated,” Evans says. “But depending on where things go it could be something we look more closely at.”

Until a viable alternative power source is found, all the outboard makers say their priority is developing current technology to produce the cleanest and most fuel-efficient engines as possible.

Different strokes

Yamaha, Mercury, Honda and Suzuki are focusing on further refining four-stroke engines while BRP has committed itself to its unique E-TEC direct injection two-stroke motors. Mercury’s Ken Evans points to 20 per cent fuel efficiencies achieved across Mercury’s flagship supercharged Verado range by reducing friction – basically making the engines run more smoothly – as an example of how easily the performance of modern engines can be improved.  

According to Yamaha’s Brett Hampson, one of the most promising developments in outboards will be the advent of DI four-stroke.

“Four-stroke engines will become more and more popular because of the fuel crisis,” Hampson says. “Yamaha is the global leader in four-stroke technology and we’ve only just scratched the surface in what we can do with these engines. DI four-strokes are a real possibility in the not too distant future. We’re looking at reducing current fuel usage by 20 to 25 per cent with DI technology, especially at low revs.”

All the outboard majors see “clean” technology as the way forward, both in regards to improved fuel efficiency and environmental benefits. BRP’s Dupont, as well as Honda Marine’s Rod Day and Haines Suzuki’s Greg Haines, are actively pushing for fuel-guzzling “dirty” two-stroke engines to be banned.

Market forces may mean, however, that there’s no need for any government legislation banning old style two-strokes. There’s little doubt that the fuel crisis has sounded the death knell for traditional two-stroke Carbi engines over about 115hp. Sales of these bigger carby two-strokes have plummeted in recent months, no doubt due to the heavy fuel use typical of these old technology engines. But smaller two-strokes will remain popular with many boaties, says Mercury’s Ken Evans, who scoffs at the no-carby two-stroke campaign being waged by his competitors. “The fuel and pollution issues with these small outboards is nothing, it’s negligible,” Evans says.



Re-powering is a definite growth area in the boating market. A lot of fishos worried by interest rates and rises in the cost of living are forgoing a new boat in favour of rigging their old boat with a fuel-efficient new engine. All the outboard players report significant consumer interest in fitting four-stroke and DI two-stroke engines on the transoms of boats previously powered by carby and EFI two-strokes.  

That said, if you are looking at a new boat make sure you consider which type of boat will give you the best performance in regards to minimising fuel use. Queensland-based Greg Haines, whose family company makes Haines Signature, Traveller and Seafarer fibreglass boats and distributes Suzuki outboards, actively promotes the benefits of fibreglass hulls in achieving the best possible fuel performance. “Our Signature variable deadrise hulls plane at troll speed. This means they can be up to three times more efficient than other hull types.”

Composite materials and new boat building techniques – like the resin injected vacuum assisted low emission process used by Haines Signature for several new models including the popular 485 SF – will reduce weights of boats and engines, providing the potential for increased fuel savings.

All five of the outboard majors say they dedicate considerable resources to training staff, boat builders and dealers on delivering the optimum performance of any boat and motor package.

In a pro-active move designed to ensure the customer gets the best performance out of a new boat, Yamaha is testing popular boat models in its dealer network range to match engines with hulls. “And our technical academy is teaching dealers to set up engines properly,” Brett Hampson says.

How you drive a boat will make a big difference to your fuel use. If you don’t “trim” the boat correctly, hull performance will be significantly compromised and you’ll record shocking fuel use. Running an engine – any engine, either high-tech or old style – at full noise will see lots of fuel used. Outboard makers recommend you get the boat up on the plane and cruise at between 3000-4000 rpm, which is where most outboards are at their most fuel efficient.  

The last boat show circuit revealed that many customers are concerned about fuel prices. This means your local boat dealer should be wised up to the best ways to rig your boat up so you maximise fuel efficiency. If a dealer doesn’t seem that fussed about ensuring your boat is propped correctly, has the right size and type of engine fitted and doesn’t give you advice on driving the boat to maximise performance and fuel use, go to another dealership.

Fitting maximum horsepower – so an engine works more easily and uses less fuel as a result – and filling up with premium fuels (especially with engines designed for high octane petrol) are recommended by the outboard makers as other ways for fishos to minimise petrol use.

When it comes down to it, however, most of us don’t use our boats as much as we do our cars – much as we’d like to. Using a boat will become more expensive as fuel prices rise, but in the big scheme of things most fishos will only be paying an extra few hundred bucks a year, even if petrol gets up to $2 a litre. Most of use head out, drop the anchor, fish and then head home. Where once we paid $50 in fuel, now we may pay $70. Is that going to make you sell your boat?

Even a hard core trip out gamefishing might rise by $120 – spend a few hours drifting and cubing instead of trolling and it’ll probably equal out.

Will increasing fuel prices stop fishing in our beloved boats? I don’t think so. We’ll be smarter in regards to what we buy, more conservative in how we operate our boats and we’ll all work harder at maximising our time out on the water. None of that is necessarily a bad thing. However, it goes without saying that if someone can invent an outboard that runs on cheap, renewable fuel, he or she will become very rich very quickly!

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