Suzuki DF 25 Service Manual page 148

NOTE:
Clean and assemble cylinder head and valve, components.
Fill intake and exhaust ports with solvent to check for leaks be-
tween valve seat and valve.
If any leaks occur, inspect valve seat and face for burrs or other
things that could prevent valve from sealing.
VALVE GUIDE REPLACEMENT
Be careful not to damage cylinder head when replac-
ing valve guide.
(1) Using valve guide remover, drive valve guide out from com-
bustion chamber side towards valve spring side.
09916-44310 : Valve guide remover
NOTE:
Do not reuse valve guide once it has been removed.
Always use a new valve guide (oversize) when assembling.
(2) Ream valve guide hole with 10.5 mm reamer to true hole
and remove burrs.
09916-37320 : Valve guide reamer ( 10.5 mm)
09916-34542 : Reamer handle
NOTE:
Turn reamer clockwise, never counterclockwise.
POWER UNIT 7-31