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8.1
8
Section 8
Disassembly
General
Clean all parts thoroughly as the engine is
disassembled. Only clean parts can be accurately
inspected and gauged for wear or damage. There
are many commercially available cleaners that will
quickly remove grease, oil, and grime from engine
parts. When such a cleaner is used, follow the
manufacturer’s instructions and safety precautions
carefully.
Make sure all traces of the cleaner are removed before
the engine is reassembled and placed into operation.
Even small amounts of these cleaners can quickly
break down the lubricating properties of engine oil.
Typical Disassembly Sequence
The following sequence is suggested for complete
engine disassembly. The sequence can be varied to
accommodate options or special equipment.
1. Disconnect spark plug leads.
2. Shut o
ff
fuel supply.
3. Drain oil from crankcase and remove oil
fi
lter.
4. Remove oil cooler.
5. Remove mu
ffl
er.
6. Remove air cleaner assembly.
7. Remove thro
tt
le control panel.
8. Remove external governor controls.
9. Remove li
ft
fuel pump and fuel pump module.
10. Remove thro
tt
le body.
11. Remove Electronic Control Unit (ECU).
12. Remove ECU bracket and electric starter motor.
13. Remove grass screen.
14. Remove outer ba
ffl
es and blower housing.
15. Remove Oil Sentry™.
16. Remove oil temperature sensor.
17. Remove inner ba
ffl
es and breather cover.
18. Remove valve covers.
19. Remove cranksha
ft
position sensor.
20. Remove manifold absolute pressure (MAP)
sensor.
21. Remove fuel injectors.
22. Remove intake manifold.
23. Remove spark plugs.
24. Remove cylinder heads and hydraulic li
ft
ers.
25. Remove fan and
fl
ywheel.
26. Remove stator and backing plate.
27. Remove closure plate assembly.
28. Remove camsha
ft
.
29. Remove governor cross sha
ft
.
30. Remove connecting rods with pistons and rings.
31. Remove cranksha
ft
.
32. Remove
fl
ywheel end oil seal.
Disconnect Spark Plug Leads
1. Disconnect the leads from the spark plugs. See
Figure 8-1.
NOTE: Pull on boot only, to prevent damage to
spark plug lead.
WARNING
Accidental Starts can cause severe
injury or death.
Disconnect and ground spark plug
lead(s) before servicing.
Accidental Starts!
Disabling engine. Accidental starting can cause severe injury
or death. Before working on the engine or equipment, disable
the engine as follows: 1) Disconnect the spark plug lead(s).
2) Disconnect negative (–) ba
tt
ery cable from ba
tt
ery.
Figure 8-1. Disconnect Both Spark Plug Leads.
Summary of Contents for Command PRO CH749
Page 1: ...SERVICE MANUAL ECH630 ECH749 HORIZONTAL CRANKSHAFT ...
Page 2: ......
Page 4: ......
Page 76: ...6 6 Section 6 Lubrication System ...
Page 94: ...7 18 Section 7 Electrical System and Components ...
Page 112: ...8 18 Section 8 Disassembly ...
Page 126: ...9 14 Section 9 Inspection and Reconditioning ...
Page 153: ......