Yamaha has a new four-cylinder engine with 7600 rpm and 200 hp

By | March 17, 2024

Yamaha has a new four-cylinder with 7600 rpm and 200 hpCar and driver

The debut of a new engine used to be a semi-regular occasion. As cars evolved, so did their powerplants, and manufacturers regularly made seven-figure investments to develop new engines. Now that the EV transition is in full swing, this is no longer the case. Major companies such as Volkswagen have announced that there will be no new combustion engines in the pipeline and several manufacturers have promised to switch completely to electric vehicles by 2040.

But the marine industry is a different story, and in recent years some of the coolest new engines—Mercury’s V-12 and Honda’s V-8—have been designed for boats. That’s also the case for Yamaha’s new 1.9-liter four-cylinder, which produces 200 horsepower at 7,600 rpm and can be found in the high-performance WaveRunners and jet-drive boats. It’s not designed for cars, but the Lemons racers among us can dream.

The 1.9-liter four-cylinder replaces Yamaha’s 180-horsepower 1.8-liter mill, blurring the performance line between the company’s naturally aspirated and supercharged engines. Yamaha’s supercharged 1.8-litre makes 255bhp, but in a WaveRunner there’s no real-world difference between the boosted 1.8 in an SVHO model and the naturally aspirated 1.9 that powers HOs. Personal watercraft manufacturers adhere to an agreement similar to the old German pact to limit top speed to 155 mph, except that on the water the target is 65 mph. That specification includes a fudge factor of 2 km/h, which of course means that PWCs with enough horsepower will reach an electronically limited speed of 107 km/h. Since a 200 hp WaveRunner can reach that limit, the only difference is how fast you get there.

a man riding a waverunnera man riding a waverunner

High-Output models now get the 200 hp 1.9-liter four-cylinder.Car and driver

As a new design, the 1.9-liter benefits from a bundle of changes aimed at sustainability and refinement. One example: There is an extra bolt that connects the cam chain housing to the block – a small adjustment that makes a big difference. “The cam chain chamber is cast from thin aluminum,” says Mark Sagers, senior technical specialist at the watercraft factory (in other words, the guy who knows all the engines inside and out). “That big, straight piece of aluminum is like a soundboard and amplifies the noise of the cam chain. But if you run a fastener from that piece to the main casting, that sound is knocked all the way down. That’s important when you’re sitting right on top of the engine and actually bolted to a guitar body.”

Performance-enhancing upgrades include a new exhaust manifold with special pipes for cylinders one and four, an increased bore size from 86mm to 88mm and a channel to direct cooling water between the exhaust valves to cool the valve seats. The 1.9 even uses about half a liter less oil than the 1.8, because Yamaha determined it could reduce air losses (read: more horsepower) without sacrificing durability. And durability versus performance is always a trade-off, whether you’re in the field or not. “On a 250cc dirt bike, the maintenance schedule calls for a new piston every nine hours and it delivers specific power like a NASCAR engine, or almost Indy,” says Sagers. “Boats perform less well, so we can make them last thousands of hours.”

a person riding a waverunnera person riding a waverunner

WaveRunner engines spend much of their life idling or at full throttle.Car and driver

A car engine can reach its peak power above 7000 rpm, but it is not expected to spend much time there. An engine intended for a WaveRunner is a different story. “Many of the durability tests are performed fully loaded at full throttle,” says Sagers. “These will last a very long time at WOT. Waverunners often run at idle or WOT, and there is no middle ground. But I have seen Waverunner engines with over 1,500 hours and no major mechanical work. It’s mind-boggling that these mechanical things can survive by this.”

Yet 200 hp is not enough for everyone. Logically, it seems inevitable that this engine will be supercharged and the 1.8-liter retired. Boost forecasters might find a clue in the Coast Guard-mandated 1.9-liter intake flame arrester; the intake manifold is molded around it so it cannot be sucked into the engine. That’s the kind of thing that would probably only happen if intake got a big boost. Maybe that will be the case soon.

the motor in a waverunnerthe motor in a waverunner

That X-shaped hood is made from a new composite that uses plant-based cellulose nanofiber resins.Car and driver

In the meantime, you can break the 200 hp barrier without forced induction. And for twin-engine boats, that means Yamaha is packing 400 hp into some of its 22-footers, which we think would mean a top speed of over 30 mph, as the 210 FSH reached 48.0 mph with the 1.8 and their total of 360. horsepower.

the twin engines in a Yamaha 220 fsh boatthe twin engines in a Yamaha 220 fsh boat

Yamaha puts two in the 220 FSH, and 400 horsepower in a 22-foot boat sounds like a good time to us.Car and driver

Yamaha has built some nice car engines, the best known being the Ford Taurus SHOs, but those of us dreaming of Yamaha-powered 200-horsepower Miatas will probably have to wait a while before these latest examples start showing up in the salvage yards. (You can spend that interim figuring out how to modify a closed cooling system, since the jet drive on these engines doubles as a water pump.)

Calling a power plant a “boat engine” is traditionally pejorative, meaning a piece of low-speed iron, an old-fashioned shipyard better suited for mooring. But engines are electric, and that’s where things are headed on the highways. So if you appreciate the mechanical complexity and cleverness of engines, boats are the new – and perhaps final – frontier.

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