The new Honda BF115 is arriving at Honda Marine dealers and at boat builders, and it offers some significant upgrades over the 115-hp model it will replace. This is not an all-new motor. It shares its 2.4-liter (143.6 cu. in.), four-cylinder powerhead with the BF150 and BF135 models, and is sort of a “de-tuned” version of those motors. The previous Honda BF115 displaced 2.3 liters, so this new model should deliver a little more bottom-end grunt just because it has more displacement. And despite being slightly larger, the new BF115 weighs about 18 pounds less than the motor it replaces, thanks to a lightweight cowl and a new composite intake manifold.
This new motor is equipped with two Honda systems we’ve seen on previous models. The engine management system employs an oxygen sensor in the exhaust as a component of its “lean burn” function that constantly fine-tunes fuel delivery to let the motor run as lean as 18:1 (air: fuel), mostly at steady cruising speeds, improving fuel economy by 20 percent, according to Honda. Like Honda outboards from 40 to 90 horsepower, the new BF115 is equipped with Boosted Low Speed Torque (BLAST), another engine-management system intended to improve hole-shot performance by executing a momentary advance of the ignition curve and adding a booster-shot of fuel when the boat is accelerated onto plane. Finally, the new 115 has Honda’s latest gearcase design with a more hydrodynamic shape and a larger anti-cavitation plate. Other items of note are a generous 50-amp alternator (40 amps to the boat), and NMEA-2000 compliance so the motor will interface with like-minded electronics.
Honda rightly points out that the BF115 has more displacement than any other motor at this rating. The Mercury and Yamaha 115 four-strokes are 1.7 liters, while the Suzuki 115 displaces just under 2.0 liters. However, even at its new, lower dry weight of 478 pounds with a 20-inch shaft, the Honda is also the heaviest motor of the group, by 79 to 64 pounds, not an insignificant difference on some boats. Like many other Honda motors, this one uses a powerhead based on an automotive engine, in this case the one used in the Accord, while its competitors use purpose-designed powerheads. Honda makes great engines, so there’s nothing wrong with leveraging that capability. But it also means that Honda Marine frequently ends up with an engine that’s really bigger than it needs to be. There are times when that displacement is an advantage, but it would be cooler to see Honda tune up its 1.5-liter, 359-pound BF90 to 115 horsepower. Maybe that’s asking too much and expecting Honda reliability in the bargain. The real sweet spot probably lies at about 2.0 liters.
I have not yet had a chance to run this motor. I expect it will be especially adept at pushing heavy pontoons and wide-beam fresh-water fishing boats, where its oomph will be handy. Honda says pricing starts at $12,818. There is no tiller kit offered for this model.