Vividguzzi

I have recently bought a 2004 V11Tenni, it has a button on the key. I had never used this button and the bike has always started but last Friday I took it for an MOT and when I went to start it she just turned over but wouldn't start. The proprietor of the shop came out took the key out, pressed the button and she started. The next day I went for a ride, must have stopped and started the bike at least 5 times with no problem, then went to a mates house to show it off and guess what? She wouldn't fire. There is no prime sound from the fuel injection although she will turn over. Please forgive the long story but the question is, have I got an after market immobiliser, if so I will have to find it and remove it or, is this factory fitted, if so is there a cure?