Not sure what machine you have but the radiator will find it's own level, if you are filling it cold, it's going to expand when hot and flow out.
Leave it be and check the level now and then, I'll bet you'll notice once it reaches the level it needs to be your leakage will stop.
2010 Prowler XTZ 1000-
27" Grim Reaper Tires/Home Made Roof/Arctic Cat Mirror/Quadboss Folding Windshield w/ home made support bar/LED Tail-Brake lights//Venom 4000 lb Winch/Amsteel synthetic line/Home Made Doors/Custom Adjustable Seats/Custom Oh Crap bar for passenger/Tonneau Cover/Fat Max storage Box in bed
Tiger Tail Towing system