Suzuki DF 40 Service Manual page 170

6-27 POWER UNIT
Camshaft identification
DF40 and DF50 camshafts differ as indicated below.
Model
DF40
DF50
Camshaft runout
Position camshaft between two "V" blocks and measure runout
using a dial gauge.
09900-20606 : Dial gauge
09900-21304 : "V" block set
09900-20701 : Magnetic stand
Camshaft runout
Service limit : 0.10 mm (0.004 in.)
If measurement exceeds service limit, replace camshaft.
CAMSHAFT JOURNAL
Check camshaft journals and camshaft housing for pitting,
scratches, wear or damage.
If any of the above conditions are found, replace camshaft or
cylinder head with housing.
NOTE:
Camshaft housing and cylinder head must be replaced as a
set.
Identification Groove
No groove
Groove
IN EX
Groove