Suzuki DF 25 Service Manual page 145

7-28 POWER UNIT
Valve stem runout
Measure valve stem runout.
09900-20602 : Dial gauge
09900-20701 : Magnetic stand
09900-21304 : "V"blockset
Valve stem runout
Service limit : 0.05 mm (0.002 in.)
If measurement exceeds service limit, replace valve.
Valve head radial runout
Measure valve head radial runout.
09900-20602 : Dial gauge
09900-20701 : Magnetic stand
09900-21304 : "V"blockset
Valve head radial runout
Service limit : 0.08 mm (0.003 in.)
If measurement exceeds service limit, replace valve.
Valve head thickness
Measure thickness T of valve head.
09900-20101 : Vernier calipers
Valve head thickness
Standard :
IN 1.0 mm (0.04 in.)
EX 1.3 mm (0.05 in.)
Service limit :
IN 0.5 mm (0.02 in.)
EX 0.7 mm (0.03 in.)
If measurement exceeds service limit, replace valve.
45˚