Make sure that the float is not cracked on the top of the unit. Mine was and the unit would tend to tip over and it would not run straight. If your float is cracked you can use a 3 or 4 inch piece of pool noodle as a temp fix. Taped on with duct tape. The float should only be big enough so that the unit sinks but it stays upright with all four wheels on the ground when the unit is not running. Too big and the legend won't sink or runs with the back end up in the water.