2009 Yamaha F40 Outboard Service Manual, Page 172Get this manual
Fuel system Float height (reference data): 30.7 mm (1.21 in)
When adjusting the float height, do not bend the lever Bend both portions of equally, when bending of the float2Check the floatReplace if there is deterioration3Check the filterClean if there is dirt or residues
Assembling the vapor separator
1Install the plates and b, and then tighten the float chamber plate screws to the specified torque