Portuguese company: http://xrwracing.com/
Look for yamaha then raptor 350 they are the Racing model
They are similar to this ones but without the kickstart gap because this ones are for Banshees
Well the pics are hosted on the builders page. Wich u can see all the other race quad they built,450 etc
They are like Duncan , i do know whos the owner i will see if he signs up but if not will gather all the specs and then post it.
http://myworld.ebay.com/jorpi-bike/?_trksid=p4340.l2559
This guy may have them.
I think they stoped making them, but they have another model (uglier i think)
http://www.xrwracing.com/site/yamaha