Where is the second v.i.n. number on my motorcycles engine?

i have a 2008 moto bravo 200 cc mini chopper,when i tried to register it they said besides the v.i.n. on the frame,there has to be that same v.i.n. on the motor somewhere???looked every where. there is another set of numbers stamped on the motor,but not another of the same vin. we even called the manufacturer , and all they said was they stopped making these bikes..does anyone have one of these bikes and knows ,? also, does anyone know where i can find a link to download this bikes owners manual? greatly appreciate any help i can get. thank you