2003 Kawasaki KLF250 Service Manual., Page 120Get this manual
7-4 ENGINE LUBRICATION SYSTEM Specifications
Item Engine Oil Type Viscosity Capacity Standard API SF or SG API SH or SJ with JASO MA SAE 10W-40 2.0 (2.11 US qt) (when filter is not removed) 2.1 (2.22 US qt) (when filter is removed) 2.75 (2.91 US qt) (when engine is completely dry)