Powering Up Commercial Mowing

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Only now, looking back, is it possible to see how much the 2008-2009 recession changed the game for landscape contractors. As the housing market imploded and contractors saw their design/build project pipelines evaporate, many of them realized they must find predictable sources of revenue to remain in business. Consequently, many owners added contract mowing to their companies or more aggressively chased that portion of their service mix.

Also, the recession, resulting in unemployment rising above 10 percent at its peak, unleashed a fresh crop of “professional” cutters. Many of them entered the industry with poor or non-existent business skills.

These forces impacted (and continue to impact) commercial mowing by putting even more pressure on how much property owners are willing to pay to have their properties maintained.

The mantra in professional mowing these days is pretty simple—keep your mower blades whirring and do all that you can to reduce mowing costs.

The same forces also drive the manufacturers of engines for commercial mowers. Major engine companies are challenging their teams to design and manufacture commercial engines that deliver more power and speed, while also taking fuel efficiency to new limits. This will be evident at this year’s Green Industry & Equipment Expo in Louisville this month.

This year, both Briggs & Stratton and Kohler are previewing significant new engine series at the GIE+EXPO. They claim these new engines will meet contractors’ demands to mow more efficiently and also to reduce mowing costs. Both companies are talking with mower OEMs. You will begin seeing commercial mowers with their new engines in dealers’ showrooms in 2015.

The efforts by Briggs and Stratton and Kohler to bring new engines to the market are the result of several years of development by each company.

More productivity at a lower cost

“Starting in 2008 we began to see some key new trends in the mowing market,” says Mark Johansen, director of marketing for Kohler Engines. Contractors began purchasing mowers with higher horsepower and larger cutting decks to boost productivity and to lower mowing costs, he explains.

One of the key factors to reduce mowing costs is to reduce fuel usage. Less fuel used means lower fuel costs.

To meet both of those criteria, Kohler and Briggs & Stratton are bringing new electronic fuel-injected (EFI) engines with higher horsepower to the commercial mowing market. Kohler is also announcing two new propane-fueled 824cc Command Pro engines.

Let’s start with Kohler’s two new propane 824 engines. The model PCV850 is rated at 27 hp and the PCV860 at 29 hp. The propane 824 was developed off of the technology of Kohler’s new gasoline-fueled 824cc Command PRO EFI. (More on that later.)

Why another propane EFI engine? The propane 824 provides more power and torque than Kohler’s previous propane PCV740 EFI engine series, which were offered on Exmark and Toro mowers in 2014. The new propane 824 offers the same fuel-saving and environmental benefits but at a larger displacement and other features to boost mowing performance.

EFI gasoline engines save more than 20 percent in fuel costs compared to similar-sized carbureted engines. Add the additional savings offered by propane, which is less expensive than gasoline, and end users can reasonably expect to save about 40 percent in mowing fuel costs.

Johansen explains that fuel represents 48 percent of the cost of owning a mower over its useful life.

In terms of the environment, propane releases significantly fewer greenhouse gas emissions. And because EFI engines use fuel more efficiently than gasoline engines, thereby using less fuel, there are even fewer emissions.

Kohler doesn’t want “to drive the mowing market” to propane, says Tom Cromwell, group president of Kohler Power. In any case that’s unlikely, at least in the short term. Propane-fueled mowers account for less than 5 percent of the mowing market.

Read more: Are EFI and Propane Game Changers?


Closed Loop EFI and Open Loop EFI

Open Loop System (EFI)

  • ECU (electronic control unit)-Reads engine RPM
  • Fuel Pump – Pressurizes fuel and sends fuel to injectors
  • Injectors – Injects fuel into cylinders
  • How it Works: ECU controls amount of fuel injected into cylinders bases on engine RMP “MAP.” MAP stands for manifold absolute pressure.
  • Pros: Less expensive, simple, easy starting
  • Cons: Less than 10 percent efficiency gain
  • Manufacturer: Kawasaki engines

Closed Loop Systems (EFI)

  • ECU – Reads engine RPM and unused oxygen
  • Fuel Pump – Pressurizes fuel and sends fuel into injectors
  • Injectors – Injects fuel into cylinder
  • O2 Sensor – Measures unused oxygen in the exhaust (engine load)
  • How it Works: ECU controls amount of fuel injected into cylinders based on 2D “map” of engine RPM and load.
  • Pros: Up to 25 percent efficiency gains, easy starting, lower emissions. MAP stands for manifold absolute pressure that keeps a constant reading on manifold vacuum, which it sends to the ECU.
  • Cons: More expensive
  • Manufacturers: Kohler Command Pro 824cc Briggs & Stratton 810cc Vanguard EFI

Source: Mutton Power Equipment, Fort Wayne, Indiana


Cromwell says Kohler is determined to remain the leader in offering gasoline-fueled engines featuring closed loop EFI. He points to its new gasoline 824, which will be available in four models, from 27 to 33 hp.

“We’ve invested in a work-hour equivalent of six years of design simulation. The 824 exceeds commercial-duty standards and is being released to the market after more than 7,500 hours of testing,” adds Johansen.

“When it comes to engines, you often have to choose between power and fuel efficiency. With the 824, you get both. This engine is designed to help commercial cutters through the toughest jobs while reducing downtime and minimizing fuel costs,” he continues.

Kohler is producing the 824cc Command PRO EFI models at its commercial plant in Kohler, Wisconsin. The 824 assembly line is outfitted with new robotics and inspection technology.

Briggs & Stratton unveils EFI engines

Briggs & Stratton is the world’s largest manufacturer of air-cooled gasoline engines, primarily for outdoor power equipment. In 2014, Briggs & Stratton Commercial Power launched its new Vanguard 810cc commercial engine series.

These engines are hand assembled at the Vanguard Certified Center located in the Briggs & Stratton Auburn, Alabama plant. Production of the 810 started in January 2014 at 20 engines a day. As this is being written the line is producing 50 engines per day with a goal of reaching 100 units.

Company-certified technicians are hand-building Briggs & Stratton’s new Vanguard 810cc commercial engines at its Auburn, Alabama, plant. PHOTO: RON HALL

This year, the company is offering the 810 with automotive-style, closed-loop EFI.

“Productivity continues to improve even with the addition of the EFI engine launch in July. All of our key quality and productivity metrics have exceeded expectations. Additional investment is being made to the line to reach the higher production demand,” says Dave DaBaets, vice president for North American Operations.


More than a dozen manufacturers of professional zero-turn mowers feature Kawasaki engines on their products.

Kawasaki Points to Usable Horsepower

Kawasaki Commercial Engines rounds out the “Big 3” as a supplier of power plants to the professional zero-turn mower market.

Kawasaki V-Twin engines, found on more than a dozen brands of commercial zero-turn mowers, are appreciated for their smooth power output, quiet operation and their durability.

Kawasaki offers engines in a range of horsepower ratings in its V-Twin, vertical-shaft commercial engine series.

For example, its FS Series features six models from 14.5 hp to 25 hp. The 13 models in its commercial FX Series range from 15.5 hp to its 37-hp FX1000V commercial engines.

Several of the company’s more robust engines are also available with its Direct Fuel Injection technology.

Both the FX1000V engine and the FX921V engine, also 999cc, are available with the company’s low-pressure fuel injection with

electric fuel pump for easy starting, choke-free operation and electronic altitude compensation.

The company says that its “Kawasaki Critical Power” engines have been tested in accordance with and were determined by using measurements according to SAE J1995. The company took that step to help clarify consumer understanding of the usable power provided by engines. The testing provides end users with realistic power out number.

The company adds, however, the actual power output of engines will vary according to numerous factors, including operating speed of the engine in application, environmental conditions and maintenance, among other factors.

The Kawasaki FX, FS and FR engines are manufactured in Maryville, Missouri.


Available in 24, 26 and 28 gross hp engines, the 810 EFI offers fuel savings up to 25 percent compared to a carbureted engine with the same displacement, says the company.

Vanguard 810cc EFI engines offer unique diagnostic features to arm fleet or dealer technicians with information to eliminate downtime and optimize engine performance.

Three diagnostic options include: in-field blink codes, supported by Vanguard’s power code; a scan reader that can be plugged into the service port to display error codes; and a cable connecting the ECU (engine control unit) to a computer to do a deeper dive into engine data.

“Landscape contractors expect two things out of their ZTR engines: peak performance and fuel economy,” says Dan Roche, marketing manager for Briggs & Stratton Commercial Power. “The Vanguard 810cc EFI engine exceeds at both by offering better fuel efficiency and operating at the 810cc displacement sweet spot that research shows is best to maximize productivity.”


From Kohler: Advantages of Closed Loop EFI

Replacing the carburetor on internal combustion engines, closed-loop electronic fuel injection (EFI) systems precisely meter fuel, resulting in optimal engine performance, reducing fuel consumption and remaining within compliance with emission standards.

While the engine is operating, an oxygen sensor in the muffler continuously monitors the composition of the exhaust gas, making adjustments to the air/fuel mixture being delivered to the combustion chamber.

Unlike open loop systems, a closed loop EFI system delivers the exact amount of fuel needed by releasing fuel sequentially at the optimum time to each cylinder. The EFI system adjusts for all operating conditions and loads over the life of the engine.

EFI provides consistent easy starts, lower fuel consumption, improved load pickup and optimal performance.

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