Cylinder Inspection - Suzuki SFV650 Service Manual

Valve Spring
The force of the coil spring keeps the valve seat tight.
Weakened spring results in reduced engine power
output and often accounts for the chattering noise
coming from the valve mechanism.
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 spring does not fall within the specified range,
replace the valve spring.
Special tool
(A): 09900–20102 (Vernier calipers (1/20 mm,
200 mm))
Valve spring free length (IN. & EX.)
Service limit: 37.1 mm (1.46 in)
Valve spring tension (IN. & EX.)
Standard: 127 – 147 N (13.0 – 15.0 kgf, 28.5 – 33.0
lbs)/33.4 mm (1.31 in)
Tension "a"
127 – 147 N
(13.0 – 15.0 kgf, 28.5 – 33.0 lbs)
(A)
I649G1140237-03
" a "
" b "
I649G1140238-03
Length "b"
33.4 mm (1.31 in)

Cylinder Inspection

Refer to "Engine Top Side Disassembly (Page 1D-25)".
Refer to "Engine Top Side Assembly (Page 1D-31)".
Cylinder Distortion
Check the gasketed surface of the cylinder for distortion
with a straightedge and thickness gauge, taking a
clearance reading at several places as indicated. If the
largest reading at any position of the straightedge
exceeds the limit, replace the cylinder.
Special tool
: 09900–20803 (Thickness gauge)
Cylinder distortion
Service limit: 0.05 mm (0.002 in)
Cylinder Bore
Inspect the cylinder wall for any scratches, nicks or other
damage. Measure the cylinder bore diameter at six
places.
Special tool
(A): 09900–20530 (Cylinder gauge set)
Cylinder bore
Standard: 81.000 – 81.015 mm (3.1890 – 3.1896 in)
Engine Mechanical: 1D-54
B944H11406020
I944H1140244-01
(A)
I944H1140246-01
I944H1140245-01