Valve Face And Seat; Valve Installation - TGB EST 1000 Service Manual

5-2. ENGINE TOP END

Valve Face and Seat

▪ Check valve face and seat for burning or
pittings and replace valve or cylinder head if
there are signs of damage.
▪ Ensure to seat valves properly. Apply some
lapping compound to valve face and work
valve on its seat with a lapping tool.
▪ Measure valve face contact width.
NOTE: The location of contact area should be
in center of valve seat.
▪ Using a caliper measure valve seat width.
▪ If valve seat contact width is too wide or has
dark spots, replace the cylinder head.

Valve Installation

▪ For installation, reverse the removal
procedure.
▪ Install a NEW valve stem seal. Make sure
thrust washer is installed before installing seal.
▪ Apply engine oil on valve stem and install it.
NOTICE: Be careful when valve stem is passed
through sealing lips of valve stem seal.
▪ To ease installation of cotters, apply oil or
grease on them so that they remain in place
while releasing the spring.
▪ After spring is installed, ensure it is properly
locked by tapping on valve stem end with a
soft hammer so that valve opens and closes a
few times.
NOTICE: An improperly locked valve spring will
cause engine damage.
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