Looking for a copy of the owner's manual? You can buy one from Kawasaki.

Or download the PDF for free. Also from Kawasaki.

Ninja 400 owner's manual, via Kawasaki (https://www.kawasaki.com/ServiceManuals/Manual/EX400GJF). Look for the "Download free PDF" link above the "Add to cart" button.

http://www.kawasaki-techinfo.net/showOM.php?view_lang=EN&spec=US&book_no=99987-1994&lang_code=EN is the direct link to the Owner's Manual PDF from that page, without having to click through other stuff.