I'd try lubing the throttle cable to see if that might displace the water and fix your issue. I'd also remove the thumb level cover on the handle bars to make sure that's dry and nothing's inside plus make sure that gasket is doing it's job. Might want to remove the side cover on the carb to check the linkage between the cable and carb. I had this happen a few times on my old warrior but my friend, his brother, his father and myself have never had this happen to us(all have the 500FM). Also make sure the throttle cable isn't binding anywhere.