Doing a quick search reveals no one has posted info on this motor. Supposedly is it's a knock off or replacement for the etek.
Is selling these with the following info "CAUTION BIDDERS! SPECIAL BUILD TYPE -The rotors in these units where NEVER balanced since they were built for low-speed wind power and high-speed vibrator applications SO these units WILL vibrate a litte bit. These rotors were hand built by us here in the USA as a replacement of the original lower yield design . "..
hurm... the video in that ebay post was from a couple years ago and related to someones gokart build using a regular B&S etek (no special build etek).