Suzuki DF2.5 Service Manual page 79

VALVE SPRING
Valve spring free length
Measure the valve spring free length.
jr' C lOLi 09900-20101: Vernier
spring free length:
Standard: IN. & EX. 22.42
mm
Service
IN. & EX. 21.52
mm
the measurement exceeds the service
spring preload
Measure the valve spring preload.
09900-201 01: Vernier
Valve spring preload:
Standard:
IN.&EX.
for15mm
Service
IN. & EX. 33 N
-4.19
If the measurement exceeds the service
valve
8.05-
9.24
lbs)
replace the valve