What is difference between Two-stroke & Four-stroke engine?

         The difference between two-stroke & four-stroke engine can be carried out with various parameters as follows 

Sr. No.	Two Stroke Engine	Four Stroke Engine
1. One cycle completes	In one revolution of the crankshaft	In two revolution of the crankshaft
2. Power stroke	Obtained in every revolution of the crankshaft	Obtained in two revolutions of the crankshaft
3. Power Produced	More power is produced because light & compact engine	Less power is produced, because heavy & bulky engine
4. Cooling & lubrication	Requires more cooling & lubrication	Requires less cooling & lubrication
5. Wear & tear	More rate of wear & tear	A lesser rate of wear & tear
6. Valve & Port	Contains only ports	Contains valve & valve mechanism
7. Initial cost	Cost is less	Cost is high
8. Running cost	More running cost	Less running cost
9. Volumetric Efficiency	Less due to less suction time	More due to greater suction time
10. Scavenging requirement	Scavenging is required	No need for scavenging
11. Thermal efficiency	Low thermal efficiency	High thermal efficiency
12. Volumetric efficiency	Less volumetric efficiency	More volumetric efficiency
13. Toque produced	More torque is produced	Less toque is produced
14. Noise	Very noise	Less noise
15. Power to weight ratio	More power to weight ratio	Less power to weight ratio
16. Engine Speed	Low speed engine	Medium & high-speed engine
17. Application	Scooters, mopeds, etc	Trucks, buses, tractors, etc

See components of IC Engine HERE