ENGINE 3-27
VALVE SPRING
The force of the coil spring keeps the valve seat tight. A weak-
ened spring results in reduced engine power output and
accounts for the chattering noise coming from the valve mecha-
nism.
Check the valve springs for proper strength by measuring their
free length and also by the force required to compress them. If
the spring length is less than the service limit or if the force
required to compress the valve spring is not within specification,
replace both the inner and outer springs as a set.
% Valve spring free length (IN & EX)
Service Limit: 38.8 mm (1.53 in)
% Valve spring tension (IN & EX)
Standard: 182 – 210 N (18.6 – 21.4 kgf, 41.0 – 47.2 lbs)
at length 31.5 mm (1.24 in)
REASSEMBLY
• Install each valve spring seat.
• Apply molybdenum oil solution to each oil seal and press-fit
them into position.
"
• Apply molybdenum oil solution to the valve as shown, and
then insert them into the valve guides.
"
• Install the valve spring with the smaller pitch
A facing the cyl-
inder head.
B
Larger pitch
C
Down
182 210 N
(18.6 21.4 kgf)
31.5 mm
(1.24 in)
Do not reuse the oil seals.
When inserting each valve into the valve guides, make
sure not to damage the lip of the oil seal.
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