Checking The Valve Clearance; Replacing The Cam Chain - SHERCO 250 SEF-R Workshop Manual

Checking the valve clearance

 The valve clearance must be checked
when the engine is cold.
 Remove the spark plug and the valve
cover.
 Remove
the timing
crankcase.
 Install special tool number 1819.
 With a feeler gauge measure the clearance
between the bucket and the cam.
Valve clearance
0.15 – 0.20 mm
Intake
Exhaust 0.20 – 0.25 mm
 If the clearance is not correct then change
the discs in order to obtain the correct gap.
 Remove the discs with a magnet.
 Measure the thickness of the disc and
replace with one of the correct thickness.
Select the appropriate disc from the
existing parts catalog.

Replacing the cam chain

 Remove the camshafts (see the chapter on
the motor top end).
 Remove the clutch cover (see the chapter
on « Right side » removing the clutch).
 Remove the chain tensioner adjuster.
 Remove the cam chain.
 Inspect the cam chain (see « visually
inspecting the cam chain »).
 Install the cam chain in the opposite
manner in which it was removed.
 Reinstall the cam tensioner bolt and
tighten to the correct torque.
Torque the cam tensioner bolt to:
10Nm.
plug from the
21