How to eliminate the DC motor back emf?

From: Electronic Swear (swear_terence_at_hotmail.com)
Date: 03/04/05 

Date: 3 Mar 2005 19:09:28 -0800

A DC motor on starting and stopping, the back emf is very large even
it is in a very short period.

Motor supply is from a rectified 220Vac@50Hz without filtering
capacitor.
I would like to know, is there any filter (R,C) to eliminate this back
EMF?
If i place a mono-capacitor in between two motor terminal, will the
result is become better and reduce some back emf from motor?

If so, what capacitance is needed?

Thanks~