Checking/Measuring The Piston - KTM 250 EXC EU Repair Manual

18 ENGINE

18.4.12 Checking/measuring the piston

(All 250 models)
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Check the piston sliding surface for damage.
» If the piston sliding surface is damaged:
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Check that the piston rings move easily in the piston ring grooves.
» If the piston ring is stiff:
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303083-10
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Check the piston rings for damage.
» If the piston ring is damaged:
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Check the piston pins for discoloration or signs of wear.
» If the piston pin shows severe discoloration/signs of wear:
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Place the piston pin in the connecting rod and check the seating for play.
» If the piston pin seating has excessive play:
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(All 300 models)
–
Check the piston sliding surface for damage.
» If the piston sliding surface is damaged:
–
–
Check that the piston rings move easily in the piston ring grooves.
» If the piston ring is stiff:
–
303015-10
–
Check the piston rings for damage.
» If the piston ring is damaged:
–
–
Check the piston pins for discoloration or signs of wear.
» If the piston pin shows severe discoloration/signs of wear:
–
–
Place the piston pin in the connecting rod and check the seating for play.
» If the piston pin seating has excessive play:
–
–
Measure the piston at the piston skirt, at right angles to the piston pin, at a
distance
B
303013-10
Replace the piston and, if necessary, the cylinder.
Clean the piston ring groove.
Tip
An old piston ring can be used to clean the piston ring groove.
Change the piston ring.
Info
Mount the piston ring with the marking facing upward.
Change the piston pin.
Change the connecting rod and piston pin.
Replace the piston and, if necessary, the cylinder.
Clean the piston ring groove.
Tip
An old piston ring can be used to clean the piston ring groove.
Change the piston ring.
Info
Mount the piston ring with the marking facing upward.
Change the piston pin.
Change the connecting rod and piston pin.
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