are you sure it has an immobiliser i have a 2001 model 50cc vivacity and its not immobilised at all.buti was given mine by a neighbour who couldnt fix it beacause it had no spark and i found a hole in the side of the igntion coil and the cdi unit was fried too so i replaced them both and now shes a runner.the cdi units for these are very cheap and as far as i can recall they are also the same as the early hondas like the honda vision.lookmon ebay they are pennies even new !ps the cdi is under the footboard and the coil is behind the rear right hand side of the seat sidepanel.
adam bike doctor, August 2010