I`ve got one of these fitted to my CityX.
Don`t know if its the same model or not, but when you start the bike up the green LED should stay on for 5 seconds then go out.(ie.the engine is running)
This apparently shows correct operation...if it is not working properly the LED should do different things, like flash intermittently and so on, depending on what exactly is wrong with it.
I would suggest you check the connection to the green TPS wire on your bike as the T-tap the powerizer comes with may not have made a good connection...I soldered mine on.
If this does not work you could a) stamp on it, then fling it in the bin
b) get on to the supplier
HTH.
B