Cylinder Head Inspection - E-TON Sport 150 Service Manual

6. CYLINDER HEAD/VALVE

CYLINDER HEAD INSPECTION

Check if spark plug and valve holes are crack.
Measure cylinder head flat with a
straightedge and flat feeler gauge.
Service limit: 0.05mm
Valve spring free length
Measure the free length of intake and
exhaust valve springs.
Standard
Outer : 35.250 mm
Inner : 32.410 mm
Valve stem
Check if valve stems are bend, crack or burn.
Check the operation condition of valve stem
in valve guide, and measure & record the
valve stem outer diameter.
Service Limit: IN 4.900mm
EX 4.900mm
Valve guide
Caution
Before measuring the valve guide, clean
carbon deposits with reamer.
Special Service Tool: 5.0mm valve guide
reamer
Measure and record each valve guide inner
diameters.
Service limit: 5.030mm
The difference that the inner diameter of
valve guide deducts the outer diameter of
valve stem is the clearance between the
valve stem and valve guide.
Service Limit: IN 0.08mm
EX 0.10mm
6-8
Copyright ©2008-2009 ETON America, all rights reserved.
The narrow pitch of the spring shall face to the
combustion chamber.
5.0mm valve guide reamer
E-TON