Hi
I am new to Drupal and am having trouble with disabling what I am calling the "core menu items" for a custom menu:

My site displays certain administration menu links based on a users role. I have one user role (named "field-user") which, in the admin menu at the top, displays only four links. These links are referenced in a custom menu named "field-admin-management". I have created two new roles and have assigned identical permissions (this is per client request ??). I have also specified the "field-admin-management" menu to the new roles under Configuration > Administration > Administration Menu > Source.

The issue is:
When I log in as a "field-user" only those four menu items are being displayed (this is proper); however, if I log in as a user with either of the other two roles, the four items are being displayed ALONG WITH what I am calling the "core menu items" (the Home button, the number of users online, the search box, and the welcome message). I cannot find a way to disable these items from the menu for my two new user roles and only display the four items that they should have access to.