Suzuki claims that its new mid-sized 115hp and 140hp outboard engines are the first in their class to offer all the advantages of drive-by-wire technology.
Traditionally, mid-size outboard engines have been controlled by cables that physically push the throttle and gear shift actuators as you move the lever (usually by means of encased steel cables).
With drive-by-wire technology, often referred to as fly-by-wire, the throttle and shift controls send electronic signals down wires that then instruct the electronics at the engine end to do your bidding.
It’s a system commonly used on powerful inboard engines and increasingly on top of the range outboard engines of 200hp or more. However, this is the first time it has filtered down to more modest outboard engines of less than 150hp.
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The advantages are two-fold. Firstly drive-by-wire makes for far easier rigging by the manufacturers, who only have to route wires rather than plotting a cable run that will bind if bent too tightly around a corner or curve. But perhaps more importantly for the end user, the result is precise and super-smooth throttle and gear shift controls.
Important though these new changes are, there are a raft of other improvements. An upgraded compression ratio of 10.6:1 helps these new 2.0 litre displacement outboards achieve better top speed and acceleration by improving thermal efficiency. Fuel efficiency has also been increased compared to Suzuki’s existing DF115A and DF140A models.
Suzuki says that factory testing has demonstrated as much as 5%–7% better fuel efficiency for the DF140BG across mid-range to high-end cruising speeds. The new DF115BG has demonstrated up to 5% –6% better fuel efficiency at cruising speed.
A 40 A alternator on both models delivers improved output and battery charging performance at low idle speeds — ideal for craft with lots of electronics.
And a redesigned cowling incorporates a new air intake structure with improved water separation and a silencer/resonator system to attenuate engine sounds and provide a more pleasant boating experience at all engine speeds.
Suzuki has also made it possible to replace the oil filter simply by removing the upper engine cover, making routine servicing easier. A new oil-spill catcher surrounding the oil filter mount allows you to change the filter without making a mess. Suzuki has also added an easy-access Water Detection Fuel Filter to help protect the engine against contaminated fuel.
They are available in 508mm (L) and 635mm (X) shaft lengths and will be available to order at the end of this year. Prices for the new engines have yet to be announced.
First published in the November 2020 issue of Motor Boat & Yachting.
