Ive not had the need to rebuild mine yet so i wouldint know, im sure someone on here has had to rebuild. I cant find anything on a part number either so unless its just a generic rebuild kit for most engines or somthing im not finding much on it. However these prices here arnt bad if you wanna just get a new engine.
http://cgi.ebay.com/SMARTECH-40138-1...QQcmdZViewItem
http://cgi.ebay.com/SMARTECH-40139-1...QQcmdZViewItem