Suzuki DF 25 Service Manual page 152

Hold valve spring compressed with special tool and install valve
cotters 6.
Make sure valve cotters are properly seated in groove A.
09916-14510 : Valve lifter
09916-14910 : Attachment
09916-84511 : Tweezers
CAMSHAFT
Apply engine oil to the surface of each camshaft lobe and jour-
nal.
Install camshaft 1 from timing sprocket side.
Install camshaft thrust plate 2, then tighten screws securelyRO
POWER UNIT 7-35