SHERCO 2014 250 SEF-R Workshop Manual page 14

• Remove the cylinder head bolts (Be sure
Remove the cylinder head bolts (Be sure
to loosen them in the correct direction). to loosen them in the correct direction).
Black bolt N° 1 on the picture is longer , 3 Black bolt N° 1 on the picture is longer , 3
bolts are identical .
• Remove the cylinder head.
Remove the cylinder head.
• Remove the head gasket and the
Remove the head gasket and the
cylinder.
Motor top end:
Inspection of the cylinder for wear: Inspection of the cylinder for wear:
Measure the inside diameter of the cylinder Measure the inside diameter of the cylinder
when it is cold.
•
Inspect the inside of the cylinder for any Inspect the inside of the cylinder for any
scratches or other evidence of abnormal wear. scratches or other evidence of abnormal wear.
If the cylinder is badly damaged or worn it ylinder is badly damaged or worn it
should be replaced.
•
Since the cylinder does not wear in a Since the cylinder does not wear in a
uniform manner measure in from side to side uniform manner measure in from side to side
and up and down as shown.
If the inside measurement of the cylinder If the inside measurement of the cylinder
exceeds the tolerance limit it must be replaced. exceeds the tolerance limit it must be replaced.
(A)=10 mm
(B)=25 mm
Piston / cylinder clearance
To determine the piston / cylinder clearance as To determine the piston / cylinder clearance as
accurately as possible it is sufficient to measure accurately as possible it is sufficient to measure
the piston and the cylinder, and then calculate the piston and the cylinder, and then calculate
the the difference difference between between
Measure the diameters as shown.
Piston / cylinder clearances
Standard 0.03 – 0.05 mm
Limit 0.10 mm
the the two two values. values.
as shown.
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Standard 250 SEF- -R:
Cylinder diameter (A) Cylinder diameter (A) = 75.982±0.01 mm
Cylinder diameter (B) Cylinder diameter (B) = 75.982~77.995 mm
Taper limit 0.05 mm 0.05 mm
Out of round limit 0.05 mm Out of round limit
Standard 300 SEF- -R:
Cylinder diameter (A) = 83.982±0.01 mm Cylinder diameter (A) = 83
Cylinder diameter (B) = 83.982~83 Cylinder diameter (B) = 83.982~83.995 mm
Taper limit 0.05 mm it 0.05 mm
Out of round limit 0.05 mm Out of round limit 0.05 mm
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