ignition key

[Ben Diesel]

Check to see whether your key is bent or twisted, they can be (carefully) straightened in a vice, I've had to do this a few times. The stock ones supplied by Yamaha are quite pliable compared to those you can get cut at Timpsons or wherever. Also, if your key has a transponder fitted for the immobiliser, a Timpson's cut key will not start the bike unless the transponder is close by, such as on the same key ring.