What is the main purpose of the flywheel key?
The flywheel key shears to protect the crankshaft from twisting, which would cause a very expensive repair. A soft key allows the flywheel to move on the crankshaft when your mower blade hits a tree root, an old stump, a large dried clod of dirt, etc.
How does a flywheel work on a lawn mower?
The flywheel stores energy when torque is applied by the energy source, and it releases stored energy when the energy source is not applying torque. Today, the fins on flywheels act almost like fans, cooling the engine by distributing air around the engine block.
Does the flywheel engage the starter?
Starting a car involves the starter engaging the flywheel to produce a crank that starts the vehicle’s engine. This is the same for a large vehicle like a tractor.
What causes kickback on a lawn mower?
A lawnmower engine commonly kicks back when the shear key breaks. The shear key commonly breaks because the blade has kit a solid object and come to a sudden stop.
What happens when a flywheel fails?
Without a flywheel, the vehicle would likely stall when you engage the clutch to move the vehicle from a standstill. This is because the engine speed would drop too fast without all the angular momentum the flywheel provides.
Can you replace a broken flywheel key on a craftsman mower?
Replace a broken or sheared flywheel key using a manufacturer-approved lawn mower part. These repair steps show how to replace the flywheel key on common Briggs & Stratton engines used in Craftsman, Husqvarna, Toro, MTD, Murray, Cub Cadet, Troybilt and Ariens riding mowers and lawn tractors.
What mowers have a sheared flywheel key?
This repair guide and video shows how to replace a sheared flywheel key in common Briggs & Stratton OHV engines that power Craftsman, MTD, Troybilt, Toro, Husqvarna, Poulan, Murray, Weed Eater and Snapper walk-behind lawn mowers.
Why does my lawn mower flywheel key keep breaking?
To protect expensive engine components from damage, the flywheel key shears off if the mower blade hits an object hard enough to make the flywheel slip out of alignment with the crankshaft. Replace a broken or sheared flywheel key using a manufacturer-approved lawn mower part.
How do you replace a flywheel on a riding lawn mower?
Replacing the Flywheel Key on a Lawn Mower. Line up the notch in the flywheel with the slot in the crankshaft. Push the new flywheel key into the crankshaft slot and tap it down flush with the top of the flywheel. Reinstall the recoil starter cup and flywheel washer on the crankshaft. Thread the flywheel nut onto the crankshaft and hand-tighten it.