One last problem with my Mercury 90hp 4 cycle EFI outboard.

[wrd1972]

Did some serious boating today and can confirm 100% that the problem is fixed thanks to the new FSM float. Thanks again to all.

[Leisure Kraft]

Without seeing the hose on the motor, I cant really comment on its actual purpose.

I did disect the float and it operates off of a magnetic principal. The "bobber" has a fixed magnet ring that one it raises to its upper most position in the float body, it opens the circuit. Once the bobber drops, the circuit closes and the pump turns on to fill the FSM.

Either the magnet has lost some of its magnatism, or the encapsulated switching mechanism has simply failed and cant respond to the magnet. I tried a continuity test with a multimeter and it was never able to go closed circuit.

It probably works like those small white switches you get with the Radio Shack security systems. One side will be a magnet and the other side will be a reed switch (either normally-open or normally-closed). You test by connecting an ohmmeter (continuity) on the switch side and bring the magnet up against it; it should change states.

Glad to see it's working for you.

[GregF]

I hope it is a Hall effect device. A reed switch ls not going to last long switching a motor.