Cylinder Head - SHERCO 250 SE/R Workshop Manual

• 250-300 header gasket adjustment table.
Squish, Standard = 1.7±0.1 mm (Set back of piston = -0.05mm)
Measurement of pis-
ton's overrun or set
back (-) (X mm)
Made with a 0.5 mm
gasket
X ≤ - 0,25
-0,25 < X ≤ - 0,15
-0,15 < X ≤ - 0,05
-0,05 < X ≤ 0,05
0,05 < X ≤ 0,15
0,15 < X ≤ 0,2

CYLINDER HEAD

• Clean the cylinder gasket and cylinder head surfaces.
• Put the 2 centring pins on the cylinder.
• Position the cylinder head.
• Fit the M8 shouldered screws with new copper washers.
• Tighten three times crosswise to 25Nm.
Squish 1st measure-
ment 0.5 mm gasket
1,9 mm
1,8 mm
1,7 mm
1,6 mm
1,5 mm
1,45 mm
Thickness of gasket
to put to have a
1.7 mm Squish
0,3 mm
0,4 mm
0,5 mm
0,6 mm
0,7 mm
0,75 mm
Sherco reference
gasket(s) to be
mounted for 1.7 mm
Squish
4942
7238
3840
4932 + 4932
7238 + 4942
4943
39