Again probably too late for the original poster, but here's the answer for anyone else:
In the form > Views > select the view where you need the default input (if there's more than one view, otherwise in the one there is) > General tab > at the bottom is 'Default Values for New Submissions'.
Add a row, select the field in question from the dropdown and type in the Default value you want. Update View and that's it.
In the form > Views > select the view where you need the default input (if there's more than one view, otherwise in the one there is) > General tab > at the bottom is 'Default Values for New Submissions'.
Add a row, select the field in question from the dropdown and type in the Default value you want. Update View and that's it.