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
6-22
New Parts
Ref.
No.
Chart
No.
Model Description
Serviceable
Limit
Min. Max.
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
2/3
2/3
2
3
2/3
2/3
2
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
3
3
3
3
4
4
4
2/3
All
All
S
P
All
ABDF
JKL
CE
All
All
S
P
All
All
S
All
S
All
S
P
All
All
All
All
All
All
All
All
All
All
All
S
S
P
P
All
All
All
All
Oil pump driven gear shaft in oil pump housing ........ Diameter:
Oil pump driven gear on shaft. ..................................Diameter:
Oil pump driven gear in housing. ...............................Diameter:
Oil pump driven gear in housing................................ Diameter:
TACHOMETER DRIVE ASSEMBLY
Tachometer drive shaft in oil pump cover. ................ Diameter:
Oil seal in tachometer drive housing. ........................ Diameter:
Oil seal in tachometer drive housing. ........................ Diameter:
STARTER DRIVE
Starter shaftgear in needle bearing. .......................... Diameter:
Starter shaftgear front (bearing) journal. ................... Diameter:
Starter clutch drum on starter shaftgear .................... Diameter:
Starter shaftgear in clutch drum bearing. ..................Diameter:
Clutch spring sleeve in starter adapter. ..................... Diameter:
Starter shaftgear in ball bearing. ...............................Diameter:
Starter shaftgear in oil seal sleeve. ........................... Diameter:
Bearing in starter adapter cover. ............................... Diameter:
Oil seal in starter adapter cover. ............................... Diameter:
Starter adapter cover pilot in starter adapter. ............ Diameter:
Worm wheel gear .............................................End Clearance:
Worm wheel gear .............................................End Clearance:
Clutch spring on clutch drum. .................................... Diameter:
Clutch spring on starter shaftgear (over knurl) .......... Diameter:
Clutch spring in clutch spring sleeve. ........................Diameter:
From center line of worm gearshaft to
starter adapter thrust pads. .................................................:
Ball bearing in starter adapter. ..................................Diameter:
Worm gearshaft in needle bearing. ...........................Diameter:
Worm gearshaft in ball bearing. ................................ Diameter:
Starter worm gear on shaft. .......................................Diameter:
Starter spring on worm driveshaft ............................. Diameter:
Starter pilot to starter drive adapter. .......................... Diameter:
Starter drive tongue to worm shaft drive slot. .. Side Clearance:
FUEL PUMP
Fuel pump drive coupling to fuel pump drive ........... Clearance:
Fuel pump drive coupling to fuel pump drive gear .. Clearance:
Fuel pump drive coupling to fuel pump. .................. Clearance:
Fuel pump drive coupling to crankshaft gear .......... Clearance:
GEAR BACKLASH
Crankshaft gear and camshaft gear. ......................... Backlash:
Crankshaft gear and idler gear. ................................. Backlash:
Idler gear and magneto drive gear
(right and left) ....................................................... Backlash:
Oil pump driver and driven gears. ............................. Backlash:
--
0.0040L
0.0045 L
0.0070L
0.0045 L
--
--
0.0031L
0.748
0.0055L
--
--
--
--
--
--
--
0.080
0.025
0.012T
0.013L
0.027T
0.252
--
0.5600
--
0.0040L
--
--
0.030L
0.016
0.016
0.016
0.016
0.001 T
0.0005L
0.0015L
0.0030L
0.0015L
0.001 T
0.0015T
0.0005 L
0.7495
0.001 L
0.0005 L
0.003 T
0.0001 L
0.0000
0.0010L
0.0017T
0.001 L
0.0426
0.0016
0.015 T
0.006 L
0.031 T
0.246
0.0010L
0.5615
0.0001L
0.0005L
0.005 L
0.001 L
0.010 L
0.0035
0.0035
0.0030
0.0095
0.008
0.008
0.008
0.009
0.003 T
0.0025L
0.0040L
0.0050L
0.0030L
0.007 T
0.0065T
0.0015 L
0.7500
0.004 L
0.0020 L
0.005 T
0.0005 L
0.0015
0.0001L
0.0063T
0.003 L
0.0736
0.0166
0.022 T
0.009 L
0.038 T
0.248
0.0001T
0.5625
0.0007T
0.0025L
0.025 L
0.0065 L
0.021 L
0.0095
0.0095
0.0090
0.0155
0.012
0.012
0.012
0.013
P Permold crankcase.
S Sandcast crankcase.