Yamaha Unveils New 1.9 Liter Engine

Naturally Aspirated, 200 HP Engine Highlights New Offerings In Both WaveRunner And Jet Boat Markets

When Yamaha first brought out their 1.8-liter engine platform, t-shirts were emblazoned with the logo “There’s No Replacement For Displacement.” The company revisits that slogan once again for 2024, unveiling a naturally aspirated 1.9-liter that’s rated at an even 200 horsepower…and showcases snappy new performance to benefit both the WaveRunner and Jet Boat lines.

Supersize Me

The new 1.9 L HO (High Output) engine is a naturally aspirated, 1,898cc, 16-valve four-stroke, producing, as noted, 200 horsepower. It’s the largest displacement engine yet from the manufacturer, replacing the former 1,812cc HO motor.  It’s also, at least as of press time, the largest displacement engine yet found in the personal watercraft market.

Yamaha touts, and we noted during a July sneak peak, that the 1.9-liter engine provides both quicker and smoother acceleration in addition to its higher top speed. This is achieved through not just the increased displacement but also optimized intake and exhaust paths, as well as a 10-percent larger throttle body to provide added power and torque.

It certainly looks cool. A black anodized engine cover and exhaust manifold are stylish and sleek, with a white, X-shaped accent branded with both High Output and Yamaha logos. That engine cover includes plant-derived cellulose nano fiber (CNF) reinforced resin. It’s more than 25-percent lighter than existing resin materials and is recyclable, resulting in both a reduction of plastics and greenhouse gas emissions (primarily carbon dioxide).

The engine pushed our VX Cruiser HO test craft to a peak speed of 64 mph and an average speed of 62 mph in the humid, heat-soaked environment that was our Atlanta area test waters. That flirts with flagship numbers, all from a naturally aspirated craft that will save you money at purchase as well as continue to save every visit to the gas pump.

Added Improvements

Other features of the new 1.9-liter include improved charging system reliability, a result of sourcing cooling water for the regulator/rectifier from the cylinder head rather than the exhaust manifold. The advancement helps the water-cooled regulator/rectifier work at maximum efficiency, key to powering modern electronics.

Yamaha engineers also removed the taper on the new throttle body for “smoother, crisper response.” The new design also moves vital electronics inboard where they’re better protected during service.

Other standout features include a relocated oil fill and thermostat for easier maintenance, easier-to-access crankcase anode, new intake manifold design featuring long runners and flatter outside shape to ease engine removal, new crankcase assembly shape, and shape change at the cam gear location for better oil flow, improved lubrication and cooling and easier maintenance access.

As to the sound, it’s got a signature grunt that evokes power without being too loud to be obnoxious.

Final touches include tweaks to both impeller and intake grate design. A new impeller has been introduced for both FX and GP models, featuring more overlap to maximize acceleration. FX HO and VX HO also get a scoop added to the intake grate bars for better hookup and stability.

List Of Models

As to the lucky recipients of the 1.9-liter, think many of the former 1.8-liter models, including VX Cruiser HO, VX Limited HO, GP HO, FX HO and FX Cruiser HO.

An even larger array of Jet Boats also will be powered by the new engine, including the 19’ SX190, AR190 and 190 FSH Sport; 22’ 222S, 222SE, 222SD, 222XE, 222XD, 222 FSH Sport and 222 FSH Sport E; and 25’ SX250, AR250, 252S, 252SE, 252SD, 252XE, and 252 FSH Sport.