2003 Kawasaki KLF250 Service Manual., Page 140Get this manual
CRANKSHAFTTRANSMISSION 9-9 Crankcase
Crankcase Assembly CAUTION
Right and left crankcase halves are machined at the factory in the assembled state, so the crankcase halves must be replaced as set
Be certain that all parts are cleaned thoroughly before Blow through all oil passages with compressed air [A] to
clear any blockage in the crankcase halves and crankshaftassembly