New Honda L4 and V6 outboards test

Launching the SL25 hard from a standstill, the performance was most impressive in the upper rpm range where I could really feel the Honda VTEC (Variable Valve Timing & Electronic Control) system kick in to boost power and torque. 

At WOT, trimmed-out and ripping across the Gold Coast Broadwater, we recorded a top speed of 45.3 knots (83.8km/h) at 6150rpm. 

Equally pleasing were the recorded fuel consumption and economy, with a modest fuel burn of 87lt/h at WOT, and just 32lt/h at the optimum cruise speed of 27.3 knots (50.5km/h), pulling 4000 rpm. This translates to just 1.2lt for each nautical mile travelled. 

The BF150 is equally frugal, the twin engines on the SL25 consuming a combined 39lt/h at 4000rpm for a best economy calculation of 1.6lt/h per nautical mile. The rig proved quite speedy across the Broadwater, too, posting a top speed of 40 knots (74km/h) at 6150rpm. 

Honda’s digital controls work a treat, with smooth and responsive throttle operation and precision gear changes from the new flush-mount, drive-by-wire remote control box. The throttle box also has intuitive features such as cruise control, auto tilt, neutral lock, and troll mode. 

The L4 and V6 models four-stroke outboards are compatible with Honda’s new 7in HD operating displays that provide improved visibility and features. Triple-engine applications now include a centre engine control with a dual-lever iST binnacle or third-party joystick control, such as Dometic’s Optimus 360.

They’ve also received a number of mechanical upgrades, including an optimised combustion chamber shape, a redesigned and strengthened starter motor mount, and new oil pump and cylinder head gasket shapes for better water drainage to help prevent corrosion. 

Also new are the oil filter’s position and an oil bypass – together, these help prevent drips and leaks as well as simplifying oil changes. Improvements to fasteners and gaskets provide better corrosion protection, while extended valve adjustment intervals and iridium spark plugs will increase the time between service visits. Finally, an oxygen sensor is included for precise control of the air-to-fuel ratio.

Honda’s signature engine technologies are, of course, also included – VTEC, as well as its Boosted Low Speed Torque (BLAST) that advances the ignition curve for improved holeshot performance.

And while the new Hondas are more automated and user-friendly, and more durable and easier to service and maintain … don’t they just look great too! Personally, I’d have mine in traditional Aquamarine Silver, but the Grand Prix White colour does contrast nicely with the gloss black highlights. 

Engine type: four-stroke DOHC 16-valve

Cylinders: inline four-cylinder

Displacement: 2354cc

Bore x stroke: 87mm x 99mm

Weight: from 218kg

Alternator: 12V - 55 amp

Gear ratio: 2.14:1

Engine type: four-stroke SOHC 24-valve

Cylinders: 60-degree V6

Displacement: 3583cc

Bore x stroke: 89mm x 96mm

Weight: from 275kg  

Alternator: 12V - 90 amp

Gear ratio: 2.00:1