Checking/Measuring The Piston - KTM 1190 RC8 R EU/UK 2009 Repair Manual

30/ENGINE - WORK ON INDIVIDUAL PARTS

Checking/measuring the piston

20.13
0 0 A
0 A
0 A
A
A 0
A 0
–
Check the sealing area of the cylinder head for distortion using a straight edge and
the special tool.
Feeler gauge (59029041100) (
Cylinder/cylinder head - sealing area
distortion
» If the measured value does not equal the specified value:
–
Change the cylinder.
400376-10
–
Check the piston bearing surface for damage.
» If the piston bearing surface is damaged:
–
Change the piston and, if necessary, the cylinder.
–
Check that the piston rings can move easily in the piston ring grooves.
» If the piston ring is stiff:
–
Clean the piston ring groove.
301418-10
–
Check the piston rings for damage.
» If the piston ring is damaged:
–
Change the piston ring.
–
Use the special tool to measure clearance
groove.
Guideline
Piston ring - groove clearance
First ring (rectangular ring)
Second ring (lower compression
ring)
Oil scraper ring
400484-10
Feeler gauge (59029041100) (
» If clearance
–
Change the piston and piston rings.
–
Check/measure the cylinder. (
–
Check the piston pin for discoloration or signs of wear.
» If the piston pin has strong discoloration/signs of wear:
–
Change the piston pin.
–
Insert the piston pin into the connecting rod and check the bearing for play.
» If the piston pin bearing has too much play:
–
Change the connecting rod and the piston pin.
–
Measure the piston on the piston skirt.
Guideline
Piston - diameter
Size I
Size II
Under the edge at right angles to the
piston pin
200475-10
p. 441)
≤ 0.05 mm (≤ 0.002 in)
Tip
Use an old piston ring to clean the piston ring groove.
Info
Mount the piston ring with the marking facing upward.

≤ 0.105 mm (≤ 0.00413 in)
≤ 0.150 mm (≤ 0.00591 in)
≤ 0.180 mm (≤ 0.00709 in)
p. 441)
is larger than the specified value:

p. 147)
104.955... 104.985 mm (4.13208...
4.13326 in)
104.965... 104.995 mm (4.13247...
4.13365 in)
6 mm (0.24 in)
of the piston rings in the piston ring
148