Kawasaki produces a line of small engines used by lawn mower manufacturers such as Toro and Husqvarna in their more expensive models. When something goes wrong with the engine after the warranty has expired, a homeowner has several options, including repairing it herself. Troubleshooting a lawn mower engine may reveal problems that are relatively easy to fix.
Trouble can come from any one of the five basic systems in the Kawasaki engine: The fuel supply, compression, ignition, lubrication-cooling and governor all work together. When one or more systems has a problem, it can show up in a variety of ways. For example, if the engine doesn't start when the rewind cord is pulled, it may be from the fuel not reaching the compression chamber, the spark plug not firing in time or the piston being frozen. When the governor -- or part that keeps the engine from going too fast -- breaks, the engine may not slow down even when you work the throttle. Knowing how the systems interact allows you to start looking in the most likely place to solve the problem.
Check the fuel tank, fuel cap, shutoff valve, fuel lines and air filter as a solution for many problems. Look for water in the fuel tank, a dirty gas or air filter and any crimped or damaged fuel lines. If the engine is running poorly, move the carburetor butterfly valve back and forth to ensure the valve is working. Check the cable leading to the choke and throttle for proper movement. Most carburetor repairs and adjustments for small engines should be done only by qualified technicians.
"Pulling the plug" on a mower requires a specially made wrench socket in the proper length. After the spark plug is removed, check it for excessive oil, carbon build up and corrosion. A new spark plug must be "gapped" properly to send the correct spark to the compression chamber. A set of feeler gauges can cost less than $15 and are worth having if you want to maintain your Kawasaki engine yourself. Read the correct gap measurement from the engine manual, place the correct gauge in the spark plug air gap and press the electrode until it is forced against the gauge. Pull the gauge out and the plug is gapped correctly.
Many engine problems require specialized tools and equipment that aren't easily available to a homeowner, and the work must be done at a service center. A Kawasaki-certified center has technicians who are qualified to work on your mower. Many independent repair centers also have the knowledge and experience, but you may be taking a greater risk of an improper repair. Before you take the mower in for engine repairs, try to learn what the problem is and when it occurs. The more information you can give the repair shop, the faster a technician can find the problem. As with other types of repairs, simple jobs can quickly turn complex. Asking the shop to call you once it has diagnosed the problem can help prevent surprise repair bills.