Yanmar 1GM User Manual page 94

88 CHAPTER FIVE
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Outer rotor
Inner rotor
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Feeler gauge
9. Installation is the reverse of removal. Tighten the oil
pump reta ining screws to the tightening torque specified
in Tabl e 2. Make sure the governor flyweight assembly is
positioned on the locating pins (Figure 60). Tighten the
crankshaft nut to the torque specified in Ta ble 2.
Disassembly, inspection and reassembly
1. Remove the oil pump cover (Figure 61).
2. Lift out the inner and outer pump rotors (F igure 62).
3. Thoroughly clean all parts in solvent and dry with
compressed air.
4. Check the drive spindle and pump rotors for signs of
wear, scoring or damage. Rep lace damaged parts.
NOTE
Replace the oil pump as a unit
if
any parts
are damaged.
5. Reinstall the inner rotor in the pump body . Reinstall
the outer rotor in the pump body .
6. Measure the clearance between the inner rotor tip and
outer rotor tip (Figure 63). Compare the measurement
with the specification in Table 1.
7. Measu re the clearance between the outer rotor and the
pump body (Figure 64). Compare the measurement with
specifications in Table I.
8. Place a straightedge across the pump body. Measure
the side clea rance between the rotors and straightedge
with a flat feeler gauge (F igure 65). Compare with speci-
ficati ons in Table I.
9. Measu re the diameter of the inner rotor shaft. Measure
the shaft bore ofthe pump body. Calculate shaft clearance
and compare it with specifications in Table 1.
10. If any clearance measured in Steps 6-9 is not within
specification, replace the pump. Individual components
are not available. The pump must be replaced as a unit.
11 . Whe n reassembling the oil pump, make sure to lubri-
cate the rotors, body and shaft with eng ine oil.