1. Four- Stroke Small Engines
Transportation
Mr. O

2. Components
Recoil Start- Pull start system, connects to flywheel/crankshaft.
Flywheel- Large wheel mounted to crankshaft, stores momentum to keep engine running. Contains magneto

3. Components (cont’d)
Crankshaft- Transfers piston motion into rotation. Used as engine output.

4. Components (cont’d) Piston-creates combustion Inside chamber.
Piston rings -add compression/
clean cylinder walls.
*Connecting Rod-
Connects piston to
Crankshaft.

5. Components (cont’d) Camshaft- rotate to open and close valves.
Timing gear- Spin to control opening/closing of valves.

6. Components (cont’d) Intake valve- opens and closes to allow air
fuel mixture to enter.
Exhaust valve- opens
and closes to allow
exhaust to escape.

7. Components (cont’d)
Sparkplug- fits into cylinder head and ignites compressed fuel/air mixture.
Magneto- device which
generates electric
current when rotated.
Coil- (ignition coil) converts low voltage into high voltage needed for spark plug.

8. Components (cont’d) Fuel Tank- Stores gasoline
Air cleaner- Connects to
carburetor, cleans
incoming air.
Carburetor- regulates fuel
intake and fuel air mixture.

9. How 4 strokes work: