Sym PA12B Service Manual page 105

7. Cylinder Head / Valve
Special tool：
Valve spring compressor
Caution
Do not over compress the valve spring.
When removing the carbon deposit,
beware not to damage the components
inside the combustion chamber.
Valve cotter removal / assembly tool is
recommended when removing the valve
spring
Special tool：
Valve cotter removal / assembly tool
SYM-1471110/20
Caution
To avoid damaging the valve stem and
the cylinder head, in the combustion
chamber place a rag between the valve
spring remover/installer as compressing
the valve spring directly.
Cylinder Head Inspection
Clean the gasket residue on the matching
surface.
Check if the cylinder head has any cracks.
Measure cylinder head warp with a
straightedge and thickness gauge.
Service Limit：0.05mm
Valve Spring Free Length
Measure the free length of intake and exhaust
valve spring.
Service Limit：
Outer spring: Under 39.7mm
Inner Spring: Under 32.5mm
7-8
To this chapter contents
SYM-1471100
Valve cotter removal /
assembly tool
Valve spring compressor