Page 395 - 2019 SHOP MANUAL CRF1000/A/D

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CRANKSHAFT/PISTON/CYLINDER
INSPECTION
Inspect the following parts for scratches, damage,
abnormal wear, or deformation.
– Cylinder
–Piston
– Piston rings
– Piston pin
– Connecting rod small end
Measure each part and calculate the clearance
according to CRANKSHAFT/PISTON/CYLINDER
SPECIFICATIONS (page 1-9).
Replace any part if it is out of service limit.

PISTON RING INSTALLATION
Clean the piston ring grooves thoroughly and install the
piston rings.

• Apply engine oil to the piston ring entire surfaces
and piston ring grooves.
• Avoid piston and piston ring damage during [1]
installation.
• Install the piston rings with the marked side facing 120°
up. [1]
– "R" mark: top ring [1]
– "RN" mark: second ring [2] [2]
• To install the oil ring [3], install the spacer [4] first,
then install the side rails [5].
Stagger the piston ring end gaps 120° apart from each [3]
other.
Stagger the side rail end gaps as shown. [2]
After installation, the rings should rotate freely in the
ring groove. [4]
20 mm (0.8 in)
OR MORE
[5]

PISTON INSTALLATION
Apply engine oil to the piston pin hole inner surface.
[4]
Apply molybdenum oil solution to the connecting rod
small end inner surface.
Assemble the piston [1] and connecting rod [2] with the [2]
connecting rod "MJP" mark [3] facing to the piston
"MJP" mark [4] side.
[1]

[3]

15-13