Small engine parts identification
Page 1: Small Engine Parts Identification
Page 2: Single Piston 4 Stroke Engine
Page 3: Key Components of a Four-Stroke Gas Engine
Valve Springs: Maintain the tension on the valves.
Rocker Arm: Transfers movement from the camshaft to the valves.
Exhaust Port: Area where exhaust gases exit after combustion.
Exhaust Valve: Opens to allow exhaust out of the combustion chamber.
Intake Valve: Opens to let the air-fuel mixture in.
Ignition Wire: Connects the ignition system to the spark plug.
Cylinder Head: Houses the valves and spark plugs.
Intake Port: Path for the air-fuel mix to enter the combustion chamber.
Spark Plug: Ignites the air-fuel mixture.
Piston: Moves within the cylinder to compress the mixture.
Piston Rings: Seal the combustion chamber and control oil.
Push Rod: Transfers movement from lifter to rocker arm.
Crankcase: Houses the crankshaft and contains lubricant.
Connecting Rod: Connects the piston to the crankshaft.
Crank Shaft: Converts reciprocating motion to rotary motion.
Valve Lifter: Acts on the push rod to open valves.
Cam Shaft: Controls the opening and closing of valves.
Cam Gear: Drives the camshaft in conjunction with the crankshaft.
Page 4: Overhead Valve (OHV) Engine
Definition: An engine design where valves are located in the cylinder head above the combustion chamber.
Page 5: Fuel Tank
Function: Stores fuel for engine operation.
Features:
Usually contains a shut-off valve.
Common materials: plastic or steel.
Page 6: Fuel Filter
Purpose: Filters gas before reaching the engine to prevent contaminants.
Page 7: Pull Start
Description: Mechanism for starting an internal combustion engine by manually pulling a cord.
Page 8: Muffler
Function: Reduces noise emitted by the engine.
Page 9: Air Filter
Purpose:
Separates debris from air taken in during engine operation.
Note: Does NOT filter water.
Impact on Performance: Affects both engine performance and longevity.
Types: Comes in various shapes and sizes, commonly made of paper or foam.
Page 10: Carburetor
Function: Mixes fuel with air to create a combustible gas.
Location: Typically attached to the cylinder head or block.
Page 11: Spark Plug
Role: Part of the ignition system that generates a spark to ignite the fuel/air mixture during the power stroke.
Variability: Available in various lengths and heat ranges; not all spark plugs are the same.
Page 12: Ignition Coil
Location: Positioned near the flywheel.
Function: Produces electricity needed for the spark plug to ignite the air-fuel mixture.
Page 13: Camshaft
Description: Shaft with lobes (cams) that open and close valves as it rotates.
Function: Controls engine timing; rotates in sync with crankshaft.
Page 14: Lifter
Role: Component that rides on the camshaft to actuate the intake and exhaust valves.
Page 15: Push Rod
Function: In pushrod engines, the lifter pushes the push rod into the rocker arm, operating the intake and exhaust valves.
Page 16: Rocker Arms
Purpose: Responsible for transmitting camshaft movement to the intake and exhaust valves.
Page 17: Valve Springs
Description: Located around the valve to ensure smooth operation.
Function: Helps valves return to the closed position after opening.
Page 18: Valve Cover
Function: Also known as the rocker arm cover; covers the valve train components.
Page 19: Piston
Description: Cylindrical part with one closed end connected to the crankshaft via a connecting rod.
Function: Forces the air-fuel mixture into the combustion chamber and exerts force onto the crankshaft.
Page 20: Piston Rings
Function: Creates a seal in the piston grooves to prevent oil leaks and keeps the air-fuel mixture contained.
Installation Tips: Do not align the open ends when installing.
Types: Compression rings and oil rings.
Page 21: Connecting Rod
Description: Rod that connects the piston to the crankshaft.
Structure:
Large end (crank end) with bolts.
Small end (piston end) attached via wristpin.
Page 22: Crankshaft
Definition: Main shaft of the engine that converts reciprocating motion of the piston to rotary motion.
Use: Outputs rotary motion to perform work, such as turning pulleys and blades.
Page 23: Engine Block (Crankcase)
Purpose: Houses the crank assembly, cam assembly, and more.
Function: Contains engine oil and provides the bore where pistons operate.
Page 24: Cylinder Head
Description: Detachable part above the combustion chamber that can contain valve components (in OHV engines).
Features: Always accommodates spark plugs.
Page 25: Cylinder Head Gasket
Function: Seals the engine block and cylinder head to maintain engine compression.
Page 26: Intake Valve
Role: Allows the air/fuel mixture to enter the combustion chamber during the intake stroke; typically larger than the exhaust valve.
Page 27: Exhaust Valve
Role: Permits exhaust gases to exit the combustion chamber during the exhaust stroke; usually smaller than the intake valve.
Page 28: Flywheel
Definition: Attached to one end of the crankshaft; helps maintain a consistent engine speed during operation.
Page 29: Oil Filler Plug
Function: Used for both checking and filling engine oil levels.
Tip: Always locate this plug before performing maintenance.
Page 30: Combustion Chamber
Description: Volume of the cylinder above the piston where combustion occurs.
Page 31: Summary of Engine Parts
Key Components: Rocker arm, valve, pushrod, combustion chamber, piston, camshaft, connecting rod, crankshaft, counterbalance.
Page 32: Engine Timing Marks
Components: Include markers for OHV rocker arms, ATV specifications, fixed push rods, camshaft, valve lifters, and crankshaft.