Suzuki RM-Z250 Service Manual page 107

• Remove the valve 6 from the combustion chamber side.
• Remove the valve stem seal 7 and spring seat 8.
• Remove the other valves in the same manner as described
previously.
CYLINDER HEAD DISTORTION
• Decarbonize the combustion chamber.
• Check the gasket surface of the cylinder head for distortion
with a straightedge and thickness gauge, taking a clearance
reading at several places indicated.
• If the largest reading at any position of the straightedge
exceeds the limit, replace the cylinder head.
 Cylinder head distortion:
Service Limit: 0.05 mm (0.002 in)
 09900-20803: Thickness gauge
VALVE STEM RUNOUT
• Support the valve using V blocks and check its runout using
the dial gauge as shown.
• If the runout exceeds the service limit, replace the valve.
 Valve stem runout (IN. & EX.):
Service Limit:0.05 mm (0.002 in)
 09900-20607: Dial gauge
09900-20701: Dial gauge chuck
09900-21304: V blocks

Be careful not to damage the valve head and valve
stem when handling it.
CYLINDER HEAD, CYLINDER AND PISTON 6-13