I don’t know why but anytime i go in water over my muffler my wheeler cuts off. No water in the air box. I keep it wide open throught any water or mud. Any suggestions to whats the cause of this

I don’t know why but anytime i go in water over my muffler my wheeler cuts off. No water in the air box. I keep it wide open throught any water or mud. Any suggestions to whats the cause of this