charset

i have installed CKeditor 4.1 on my site , my sity using charset windows-1251 .

when i write words in russian language, editor converts it to utf-8 (why?).     Then i write contents of

<div id="editable1" contenteditable="true"> into text file, it is already in utf-8 charset.

how to forbid CEditor using Unicode ??   I searched settings and did find one (config.js  is too small).