Suzuki DF25/DF30 Four Stroke Service Manual, Page 151Get this manual
7-34 POWER UNIT
REASSEMBLY
Reassemble in reverse order of disassembly pay special attention to the following stepsVALVE Install valve spring seat to cylinder head
After applying engine oil to stem seal and spindle of special toolinstaller attachment ), fit stem seal to spindleThen, pshing special tool by hand ,install stem seal to valve guideCheck to be sure that seal is properly fixed to valve guide09917-98221Installer attachment 09916-58210Installer handle B