2003 Kawasaki KLF250 Service Manual., Page 48Get this manual
FUEL SYSTEM 3-11 Carburetor
the Connectdrainfuel level gauge to the open end of the carburetor hoseSpecial ToolFuel Level Gauge: 57001-1017
Fuel Level Gauge [A] Zero Line [B] Drain Plug [C] Carburetor Body Bottom Edge [D] Fuel Level [E] Hold the gauge vertically against the side of the carburetor body so that the "zero" line is several millimeters higher than the bottom edge of the carburetor bodyTurn the fuel tap to the ON position to feed fuel to the carburetor and gauge, then turn out the carburetor drain plug few turnsWait until the fuel level in the gauge settlesKeeping the gauge vertical, slowly lower the gauge until the "zero" line is even with the bottom edge of the carburetor body
Do not lower the "zero" line below the bottom edge of
the carburetor bodyIf the gauge is lowered and then raised it again, the fuel level measured shows somewhat higher than the actual fuel levelIf the gauge is lowered too far, dump the fuel out of it into suitable container and start the procedure over again