KTM 250 DUKE Owner's Manual page 91

11 SERVICE WORK ON THE CHASSIS
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Loosen screw
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Remove screw
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Remove nut
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Push the chain guard aside.
M00716-10
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Check the chain sliding guard for wear.
» If the chain sliding guard has lost material due to wear to the extent that, in
area 
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Change the chain sliding guard.
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Check that the chain sliding guard is firmly seated.
» If the chain sliding guard is loose:
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Tighten the screws on the chain sliding guard.
C00199-10
 .

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
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, drilled hole  is visible from above:
89