I am looking for some information on electric gokarts. My brother, dad and I currently run a rotax (gas) gokart. We have a spare chassis from a rebuild about a year ago. We had the rotax out last weekend and were throwing around project ideas like we always do.

Given my welding and machining skills, I thought it might be fun to build up an electric kart. If I could figure out the best solution to mate up to the existing gears/axel, we would be golden. Along with the existing chassis, we need a motor, controller and batteries.

The motor of choice seems to be Briggs and Stratton Etek-R.
http://www.robotmarketplace.com/marketplace_etek.html

Here is a soon to be commercial Kart system.
http://www.voltagp.com/

Does anyone have any information or experience building an electric gokart?

Does anyone know of any other commercial electric karts available?