Frequently Asked Questions

How does a 4-cycle (4-stroke) engine work

Are 4-cycle and 4-stroke the same thing?

Yes, “cycle” and “stroke” are the same. A 4-cycle (4-stroke) engine goes through 4 steps to generate power. A 2-cycle (2-stroke) engine, often used in small hand-held equipment, goes through 2 steps to generate power. 

How does a 4-cycle engine operate?

In a 4-cycle engine, the piston takes four cycles (strokes) to complete its movement cycle.

• Intake Stroke: The intake valve opens as the piston slides to the bottom of the cylinder which brings air and fuel into the cylinder. 
• Compression Stroke: The intake valve closes and the piston slides back up the cylinder, compressing the air/fuel mix. 
• Power Stroke: The spark plug ignites the mix, pushing the piston back down to the bottom of the cylinder. 
• Exhaust Stroke: As the piston moves back up the cylinder the exhaust valve opens and pushes the hot gasses out into the muffler.

What’s the difference between air-cooled and liquid-cooled 4-cycle engines?

Air-cooled engines are cooled by the atmosphere. They have fins that help dissipate heat, and often a fan to keep air moving over the hot engine. Liquid-cooled engines have a liquid-filled radiator and fan to help cool them. 

How to tell a quality lawnmower engine

Are all general purpose engines made the same way?

No. Kawasaki crankcases are high-pressure die cast, a more demanding method than typical sand-casting. Crankshafts are forge-quality cast iron, not powdered metal. Gaskets are high-temp silicone or metal instead of paper. Pistons are ultra-light alloy with a racing-motorcycle heritage. Flywheels are heavy cast iron to absorb shock and maintain blade speed. Everyone who assembles an engine also inpects it, and every finished engine – not just a sample – is test-run. This results in engines that are consistent, reliable and durable. 

 

Do the materials that go into an engine really matter?

High quality raw materials are critical. Kawasaki uses automotive-grade aluminum, premium steel, forge-quality iron, and industrial-strength seals and gaskets in every engine to withstand the heat, pressure and loads of heavy extended use.

Is a premium engine worth the extra cost?

The heavy use and high loads of commercial lawn mowing is extremely hard on general purpose engines. Some professional landscapers mow more in a week than a homeowner mows in a year, and a high-quality engine delivers the reliability and power to keep their lawn mowers running. That means higher productivity and profit for pros and more years of trouble-free performance in residential use. Either way, it's well worth the extra cost.

What features or details should I look for in a lawn mower engine?

Selecting a brand known for performance is the best insurance. In addition, “fit and finish” indicate a well-built engine: smooth edges along seams and covers, trimmed seals with no overlap, heavy fuel lines and plug wires, tight-fitting housings and covers. Clearly marked, easy-access dipstick and filters and convenient touches like Kawasaki’s debris clean-out ports are good indicators. In terms of power, only Kawasaki Critical Power engines are SAE Certified for horsepower accuracy, so you can be sure you’re getting all the power that’s promised. Finally, Kawasaki Genuine Partsced to the same rigid standards of Kawasaki engines, ensuring proper fit, performance and protection.

Where was my Kawasaki engine built?

Most Kawasaki lawn mower engines are assembled at the Kawasaki Motors Manufacturing (KMM) plant in Maryville, Missouri. For a look inside the factory, click here

Where are the model and serial numbers on my Kawasaki engine?

Model and serial numbers are located on a tag on the engine housing. Register your engine numbers with Kawasaki Engines (you can do that here)

Horsepower and torque

What’s the difference between horsepower and torque?

Horsepower is a rate of doing work. One horsepower is the power it takes to move 550 pounds one foot in one second. Torque is rotating force: the power it takes to turn a wheel or spin a blade. An efficient, productive mower engine requires a precise balance of both - one reason why Kawasaki engineering is so important.

How is horsepower measured?

Typically horsepower is measured on a dynamometer, according to standards defined by the Society of Automotive Engineers (SAE). Engine manufacturers can choose which SAE standard to use. Kawasaki Critical Power engines use SAE J2723, the tightest standard in the industry, with minimum 98% accuracy.

Is a bigger horsepower number better?

Not always. Depending on the rating formula used, a big number may not show actual engine power. Look for a Kawasaki Critical Power engine to be sure you get precise horsepower.

What does Kawasaki Critical Power mean?

Critical Power is Kawasaki’s horsepower rating method, based on the industry’s tightest rating standard: SAE J2723. A Critical Power rating is at least 98% accurate. More common rating methods can deliver a horsepower rating that’s just 95% accurate, meaning the engine delivers 5% less power than advertised.

Kawasaki Critical Power engines

What is Critical Power?

Critical Power is Kawasaki’s horsepower rating method using the tightest standard in the industry, to ensure consistently accurate power. Kawasaki Critical Power engines are certified accurate by SAE.

How do Critical Power engines compare to other engines?

Critical Power engines deliver at least 98% of rated horsepower. Conventional engines can deliver as little as 95% of rated power, compromising performance and productivity.

How is a Critical Power engine power-rated?

Critical Power engines are horsepower tested following the SAE J1995 method, verified by the TUV Rheinland Group, and then certified according to a strict SAE J2723 protocol. Most lawnmower engines do not use this demanding system, and Kawasaki Critical Power engines were the first to have accurate certified power by SAE.

About fuel: ethanol, E-85, premium and more

What is ethanol gasoline, and should I use it?

Regular pump gas is usually a blend of 90% lead-free gasoline and 10% ethanol (E-10). You can use this fuel in any Kawasaki lawnmower engine.

Can I use E-85 or other blends in my Kawasaki engine?

No, E-15, E-85 and other blends can damage your small engine and void your warranty.

Does it help to use premium-grade fuel?

No. Premium gas, with or without ethanol, will not improve performance or fuel efficiency.

Do I need to use a fuel additive?

Kawasaki engines are designed to run on regular pump gas. In extreme conditions, such as extended below-freezing temperatures, gas-line anti-freeze may be used. If storing fuel for more than two weeks, use a fuel stabilizer to prevent gasoline breakdown. 

Parts and accessories

Is there a difference in spark plugs, oils, and filters?

Yes. Spark plugs have specific gaps and heat ranges, and the wrong plug in your engine will affect performance. Automotive oil lacks the additives of mower oil, including high-lubricity zinc, and will not protect your engine as well. Generic air and oil filters may not fit or work properly, potentially damaging your Kawasaki engine.  

Is it ok to use generic parts and oils?

Generic filters, fluids and parts may not be made to strict Kawasaki engineering standards, and may not fit, work or protect your engine. The wrong part can ruin your premium engine.

What oil should I use in my engine? Can I use synthetic?

Kawasaki Genuine engine oils, formulated specifically for high performance constant-speed, air-cooled engines, are strongly recommended for maximum cooling, lubrication and protection. Follow this guide for proper application. For the ultimate performance in low and high temperature applications, use Kawasaki Genuine 10W-30, 10W-40 or 20W-50 synthetic blend.

Although 10W-40 engine oil is the recommended oil for most conditions, the oil viscosity may need to be changed to accommodate seasonal temperature changes. Using 20W-50 oil in higher ambient temperatures may reduce oil consumption.

Where can I find Kawasaki Genuine Parts?

Kawasaki Genuine Parts are found only at authorized Kawasaki Engines dealers. You can find a local dealer here.

Engine Maintenance, Service and Warranty

How can I keep my engine running its best?

Regular service of air filters, oil, oil filter, and the cooling system (flywheel fan, cooling fins, and any radiator or oil cooler) are the best ways to ensure performance and extend the life of your engine. Use of Kawasaki Genuine Parts eliminate any guess work. See your owner’s manual for specific recommendations.

Where can I get my Kawasaki-powered mower serviced?

See your Authorized Kawasaki Engines dealer for correct engine service. You can find your local dealer here. Some mower brands, such as John Deere, require you contact that brand’s authorized dealer for both engine and mower service. After contacting your local dealer, if you still need additional support, use the information below to contact us.

Contact Kawasaki Engines USA

tel: 877-364-6404
email: kawasakienginesupport@kmc-usa.com

Can I buy a Kawasaki replacement engine?

Yes. See your Authorized Kawasaki Engines dealer for the right engine to re-power your equipment. You can find your local dealer here.

Why does Kawasaki opt for open-loop control rather than closed-loop control?

Our open-loop system, paired with our electronic governor (eGov) and ECU achieves the results lawn care professionals want; power and reliability.

What is the difference between open-loop versus closed-loop?

Open-loop system uses a defined map to manage the air/fuel ratio on the front end of the fueling process. A closed-loop system is more complicated in that it needs to add an O2 sensor to measure exhaust.

What is the maintenance advantage for open-loop?

The design of the open-loop system requires fewer parts so there’s less to go wrong. A closed-loop system requires more parts and thus more maintenance.

Kawasaki owner manuals, service booklets and bulletins

Where can I get a specific engine owner’s manual?

Owner’s manuals are available on this website and can be downloaded here.

Where can I get my engine’s service manual?

Service manuals can be purchased from your Authorized Kawasaki Engines dealer. Find your dealer here.