2003-2006 Kawasaki KFX400 service manual, Page 68Get this manual
PERIODIC MAINTENANCE
To minimize the possibility of tire damage from over-inflation, we strongly recommended that manual type air pump be used rather than high pressure air compressor as found in service stationsWhen filling air into the tires, never exceed 70 kPa (0.7 kgfcm, 10 psi)
The standard tire fitted on this vehicle is an AT227R20$ for the front and AT2010R9$ for $ $ the rearThe use of tires other than those specified may cause instabilityIt is highly recommended to use the specified tires