Does it have HISS? (Honda Ignition Security System) if so you need the corresponding key, they were put on around 2000, a real bugger if its broken or the wrong key, i had a cbr 600 f4 with the same problem and ended up having to buy a new ecu (honda wont/cant even sell you a new key/chip), that bike had the same symptoms as your after someone had hotwired the wiring loom