Operating instructions
Table Of Contents
- 1 Introduction
- 2 General Description
- 3 Special Tools and Equipment
- 4 Disassembly
- 5 Cleaning, Repair and Replacement
- 6 Inspection
- Definitions
- Magnetic Particle Inspection
- Critical New Part Dimensions
- Fluorescent Particle Inspection
- Dimensional Inspection
- Protective Coatings
- Crankcase Inspection
- Crankshaft Inspection
- Camshaft Inspection
- Connecting Rod Inspection
- Gear Inspection
- Piston Inspection
- Cylinder Inspection
- Inspection Chart
- Crankcase Stud Heights
- Mag Particle Inspection Procedures
- Table of Limits
- Torque Specifications
- General Torques
- Table of Limits Chart
- 7 Assembly of Subassemblies
- 8 Final Assembly and Test
- 9 IO-520-M
- 10 IO-520-BB, CB and MB

2-4
FIGURE 2-2. GEAR TRAIN DIAGRAM (TYPICAL WITH SANDCAST CRANKCASE).
1. Crankshaft gear......................................................... 1:1
2. Crankshaft................................................................. 1
3. Camshaft cluster gear............................................... 1:0.5
4. Camshaft................................................................... 1:0.5
5. Hydraulic tappet ........................................................ --
6. Governor drive bevel gear ........................................ 1:0.5
7. Governor driven bevel gear ...................................... 1:1
8. Oil pump and tachometer drive shaftgear................. 1:0.5
9. Oil pump driven gear................................................. 1:0.5
10. Tachometer drive bevel gear .................................... 1:0.5
11. Tachometer shaftgear............................................... 1:0.5
12. Idler gear assembly................................................... 1:0.652
13. Idler gear support pin ................................................ --
14. Left magneto drive gear ............................................ 1:1.5
15. Right magneto drive gear.......................................... 1:1.5
16. Starter, ............................................................. 32:1
17. Worm drive shaft....................................................... 32:1
18. Worm shaft spring ..................................................... --
19. Starter worm gear ..................................................... 32:1
20. Starter worm wheel ................................................... 2:1
21. Clutch spring ............................................................. 2:1
22. Starter shaftgear ....................................................... 1:2
23. Fuel pump drive gear ................................................ 1:1