Kawasaki STX-15F - Manual (Page 150)

4-6 ENGINE LUBRICATION SYSTEM
Specifications
Item Standard
Engine Oil
Grade API SE, SF, or SG
API SH or SJ with JASO MA
Viscosity SAE 10W-40
Capacity 4.0 L (4.2 US qt, with or without the filter)
5.0 L (5.3 US qt, when engine is completely dry)
Level Between upper and lower level lines (see text)
Oil Pressure Measurement
Oil pressure @3 000 r/min (rpm),
oil temperature 74°C (165°F) 461 kPa (4.7 kgf/cm², 67 psi)