5. FUEL SYSTEM MXU 300/250 CARBURETOR CLEANING Blow compressed air through all passages of the carburetor body. Float Valve FLOAT/FLOAT VALVE INSPECTION Inspect the float valve seat for wear or damage. Inspect the float for damage or fuel level inside the float chamber. Float Valve Seat FUEL RESERVOIR O-RING CHECK Remove the O-ring. INSPECTION Inspect the check the O-ring for damage. Replace with new ones if necessary O-ring 5-13