What Is A Flywheel, And Why Is It So Important To Your Lawn Mower?

Jun 13, 2023

Mowing your lawn is an important task for summer, and knowing how to care for your lawn mower will help keep it up and running. One of the crucial components of any lawn mower is the flywheel, which is part of the engine. The flywheel enables the crankshaft to keep turning by holding onto the energy from the combustion process, and it pushes air around the engine, which keeps the mower from overheating. If the flywheel is damaged or not working properly, your lawn mower may have trouble starting or could quickly become overheated. Flywheels also contain magnets that are necessary for the engine's ignition.

Your lawn mower should clue you in if there's something wrong with the flywheel. These signs include a lawn mower that stalls frequently or perhaps won't start at all. Another telltale sign of a faulty flywheel is if you smell something burning. To ensure your mower will be reliable throughout the summer, it's best to check the flywheel for broken fins, shearing, or cracks, as well as any damage to the crankshaft.

Before attempting to check the flywheel, it's essential to disconnect the lead of the spark plug and put it in a safe place. When the flywheel is on the crankshaft, examine it to see if it wobbles, which may indicate it's damaged. If you notice anything wrong with your mower, you may have to remove the flywheel so you can replace it with another one. To do this, detach the shroud by taking off the bolts. For engines with a flywheel brake, you'll need to unhook the end of the brake spring, and if your mower has a flywheel clutch, you'll need to take it off. Make sure to hold the flywheel with a strap wrench or with a special flywheel holder while removing the clutch and any nuts holding it in place.

From there, you can attach a flywheel puller to help you remove this necessary engine part. Be sure to have the nut of the flywheel threaded onto the crankshaft, and rotate the puller's nuts until the wheel comes off. Once your flywheel has been removed, you'll also need to take the flywheel key off the crankshaft. Now, you'll be able to install a new one.

To install a new flywheel on your lawn mower, start by putting the new piece onto the crankshaft and pushing it down, aligning the flywheel's notch with the crankshaft's slot. Insert the flywheel key into the crankshaft, and secure it with the nut. If you have trouble with the blades spinning while you're trying to tighten the nut, try wedging a piece of scrap wood between the blades.

Make sure the nut is tightened to your manual's specifications, and replace the other components of your mower where they were before you removed the flywheel. Once this is done, you can reconnect your spark plug lead, and your lawn mower should be working again. Flywheels are essential for lawn mowers to function properly, so inspecting yours yearly and promptly replacing the flywheel if you notice any trouble with it will help you keep your mower in good shape.