Like any machine, mowers also need regular upkeep.
Typically, basic maintenance would never go beyond cleaning the deck and possible blade replacement, it is important that you understand how the engine works.
By knowing your lawn mower small engine parts you could even replace defective and broken parts easily; or at least you would know what is the mechanic doing when he explains the problem to you.
Important riding lawn mower parts are:
This is the cord that is used to start the engine. Depending on the model, you may or may not have to prime the engine before pulling the cord.
The newer more advanced engines do not have this cord, they instead use electric start from the battery power.
Engine Rotation Assembly:
Every engine works by rotating action and to keep this going, it uses electromagnetic concepts.
The whole operation in a gas-based engine starts from the spark plug. This ignites the fuel in the engine which starts the whole operation.
The combustion of the fuel takes place in a combustion chamber and the force of the hot air drives the revolving magnets to generate the power required to drive the mower and rotate the blades.
This is the primary input to the engine. It draws the air from outside and the fuel from the fuel tank.
The two are mixed and combusted in the combustion chamber. It is extremely critical that your carburetor does not get clogged with dirt and dust. This will degrade the performance of engine drastically
Any small engine has two valves i.e intake and exhaust. The intake value introduces the air and fuel into the chamber.
The exhaust values release the burnt fuel with hot air outside.
The two values work in conjunction to ensure that maximum energy from the combustion is transferred to the axles.
This is the unit that helps transfer the power from combustion to the axles and other rotating parts of the engine.
The piston is placed in a cylinder and connected to a crankshaft. When the fuel burns the hot air expands pushing the piston out.
When the hot air is released from exhaust value, it creates a vacuum which sucks the piston back.
The crankshaft connected to the piston, converts this back and forth movement into rotation motion.
It is the unit which shares lubricating oil. Given the mechanical movement intensive motions in the engine, it is important that the various engine parts are well oiled and lubricated.
This ensures smooth and efficient operation and also prevents the engine from over-heating.
Flywheel brake and Stop Switch:
These are not common in most other small engines, but important safety controls in lawn mowers.
Unlike other engines, the lawn mower engine must be stopped immediately once the controls are released.
This is critical from safety point of view given the sharp rotating blades.
Any engine can produce a lot of heat and if it is not cooled, it could burn out.
Cooling fins help regulate the temperature in the engine. The fins pass the air over the hottest parts of the engine to reduce their temperature.
Source from: Small Engine Care & Repair: A step-by-step guide to maintaining your small engine (Briggs & Stratton)