How to set default value in Kendo DropDownList

The value works only in jquery, not in html helper. So it works in Jquery like

    var dropdownlist = $("#PersonalCoachName").data("kendoDropDownList");
    dropdownlist.value(coachId);
    dropdownlist.refresh(); 

Use the Value-method. See example code below.

@(Html.Kendo().DropDownList()
      .Name("DropDownListName")
      .DataTextField("Text")
      .DataValueField("Value")
      .BindTo(model.DropDownListItems)
      .Value(model.Selected)
      )

EDIT: DropDownList needs to be bind to List<SelectListItem> and it can be initialized as seen below.

var items = new List<SelectListItem>
{
    new SelectListItem { Text = "Item0", Value = "0" }, 
    new SelectListItem { Text = "Item1", Value = "1" } 
};

In addition, I would recommend to use MVVM to attach it to view.

public class DropDownViewModel
{
    public String Selected;
    public List<SelectListItem> DropDownListItems;

    public DropDownViewModel(String selected, List<SelectListItem> dropDownListItems)
    {
        Selected = selected;
        DropDownListItems = dropDownListItems;
    }
}

Use the property 'index' while initializing the kendo combobox to set the Default value.

 $("#fabric").kendoComboBox({
            autoWidth: true,
            dataTextField: "text",
            dataValueField: "value",
            dataSource: [
                            { text: "Cotton", value: "1" },
                            { text: "Polyester", value: "2" },
                            { text: "Cotton/Polyester", value: "3" },
                            { text: "Rib Knit", value: "4" }
                        ],
            filter: "contains",
            suggest: true,
            index: 3
        });