PWRS 1510 2-CYCLE Fundamentals

This is a basic course in the theory of engine operation, diagnosis of problems, minor repairs, and overhaul procedures relating to 2-cycle power sports engines. The focus of the course is the application of hand-on skills relating to diagnosis and repair of single and multi-cylinder 2-cycle engines, crankshaft repair on single cylinder engines, and top/bottom end repair procedures on single and multi-cylinder engines. (1 lect., 4 lab)

Credits

3 credits

Major Topics

  • 2-cycle theory of operation
  • 2-cycle performance diagnosis
  • 2-cycle engine component analysis and failure diagnosis
  • Top end overhaul procedures
  • Cylinder resizing and repairing
  • Bottom end repair and reconditioning
  • Single cylinder crankshaft repair and truing
  • Case splitting and transmission inspection procedures.

Outcomes

In order to successfully complete this course, the student will:

1. Label the parts of a 2-cycle engine and select the description that correctly describes the function of the following parts:

1A. The piston

1B. The rings

1C. The crankshaft

1D. The cylinder

1E. The crankcase

1F. The cylinder head

1G. The transfer ports

1H. The induction system

1I. The exhaust system

2. Remove a spark plug and determine rich or lean fuel condition by examining the spark plug and the piston top.

3. Examine the cylinder and determine if there is physical damage to the upper cylinder area of the engine.

4. Remove the exhaust pipe and/or flange and examine the cylinder, piston, and connecting rod through the exhaust port to determine problems with the engine bottom end.

5. Inspect the ignition timing and determine if the timing is within specifications, then evaluate the role timing may have in engine performance.

6. Perform a compression test and evaluate the results.

7. Perform a bottom end pressure test and evaluate the results.

8. Evaluate the top end of a powersports 2-cycle engine and determine if damage exists and recommend repairs required to fix the engine.

9. Disassemble and reassemble the top end of a 2-cycle powersports engine.

10. Deglaze a cylinder and chamfer the ports correctly.

11. Use a bore gauge and a micrometer to determine cylinder serviceability.

12. Evaluate the cylinder condition and propose the most economical repair strategy.

13. Inspect the wrist pin and top end bearings for wear and damage and recommend proper repair procedures.

14. Install cir-clips correctly in pistons.

15. Install rings correctly on pistons.

16. Use the proper tools to install pistons in cylinders.

17. Examine the crankshaft, crankcases, and bottom end components of a 2-cycle powersports engine and assess the need for repair.

18. Disassemble and reassemble a 2-Cycle bottom end.

19. Inspect the engine cases on a 2-cycle powersports engine and determine the most economical repair options.

20. Inspect the crankshaft on a 2-cycle engine and determine the most economical repair option.

21. Inspect all seals, bearings and components attached to an engine and determine the most economical repair options.

22. Repair damaged threaded holes using "Heli-coil" thread repair technology.

23. Examine a 2-cycle crankshaft and diagnose needed repairs.

24. Disassemble and reassemble a single cylinder 2-cycle crankshaft using a press.

25. Examine the disassembled crankshaft and evaluate the serviceability of the components.

26. Apply the proper tools and techniques to true a single cylinder 2-cycle crankshaft to manufacturer’s specifications.

27. Apply the tools and techniques to properly install a single cylinder 2-cycle crankshaft into its case.