My Prowler 650 did the exact same thing out in Utah. We just pinched the hose in half and zip tied it. Never had an issue again.
The screw was tight, the float was right, the overflow tube was solid, never could figure out why it started draining.
2010 Desert Red Metallic XTZ 1000 Prowler -
27" Grim Reaper Tires/Home Made Roof/Arctic Cat Mirror/Quadboss Folding Windshield w/ home made support bar/LED Tail - Brake lights/Tellico Short Tailgate straps/Venom 4000 lb Winch/Amsteel synthetic line/Home Made Doors/Custom Adjustable Seats/Custom Oh Crap bar for passenger/Tonneau Cover/2-Fat Max storage Boxes in bed/Tiger Tail Towing system
Still to come