BRP Delivers New Outboard Design With Rotax

BRP says its new Rotax engine offers all of the advantages of outboard power while eliminating the clutter on the transom. This all-new propulsion unit orients the powerhead horizontally so that the entire outboard can fit below an extended transom platform. Initially offered as two models, the 115 hp Rotax S115 and 150 hp Rotax S150 are exclusive to BRP boat brands Alumacraft, Manitou and, in Australia, Quintrex.

Rotax, based in Austria, creates and manufacturers engines for BRP Sea-Doo personal watercraft, Can Am off-road vehicles, and Ski-Doo snowmobiles.

The new outboard utilizes some features and technology first seen in Evinrude outboards before BRP shut down that brand in 2020, combined with new features engineered by Rotax.

Both the 115 and 150 feature a 1.9-liter three-cylinder, two-stroke powerhead; the 150 adds RAVE variable exhaust ports for a power boost. The E-Tec direct fuel-injection system produces very low emissions and outstanding economy, especially at idle and low speeds.

Both motors come with a digital throttle-and-shift control. Power trim-and-tilt is controlled by a conventional hydraulic ram, while power steering is actuated by a hydraulic helix integral to the motor bracket. The gear case does tilt clear of the water.

Because the motor lives primarily in the water, the cast‑aluminum cover must be watertight. It’s secured with a noncompressing gasket and 15 bolts. The high-rise exhaust manifold and a check valve on the intake are designed to prevent water intrusion when the engine is not running. A water-detection probe and extraction pump expel condensation that might collect in the bottom of the engine case.

Maintenance that requires access to the powerhead is scheduled only after five years or 500 hours. Like past Evinrude models, the motor has a self-winterizing function that oils down the cylinders for long-term storage. Air enters the engine through a tube routed into the boat transom. Injector oil is carried in a 3.5-gallon reservoir within the boat. The gear case is the same found on midrange Evinrude models, with a 2.08‑to-1 ratio. It mounts on a standard outboard transom and bolt holes, and has a 25-inch length.

Rotax says that the outboard weighs 522 pounds at both its 150- and 115-horsepower ratings. That makes the 150 about 57 pounds heavier than a Mercury 150 FourStroke, and the 115 weighs about 150 pounds more than a Mercury 115 FourStroke. The Rotax comes with a three‑year/300-hour warranty.

We ran the Rotax on a 22-foot Manitou Cruise and found that the S150 produced competitive performance. Acceleration was steady, and we hit a top speed of about 35 mph with the top erected—about the same as the triple-tube Viaggio Lago 22S with a Mercury 150 we tested last year.

Tucked away below the Max Deck, the motor is smooth and quiet. We noted only about 80 dB-A at cruising speed. But the tone of the sound created by the Rotax two-stroke engine is higher in pitch than that of a four-stroke outboard, and so it doesn’t seem as quiet.

BRP says that the Rotax outboard design is “scalable,” so expect to see more-powerful versions in the future.