My rev counter issue - 6000rpm

[Dead Eye]

TPS stands for Throttle Position Sensor

If the tacho is reading 4k then it is alerting you that the speedo drive has become disconnected / stopped working. Had this on mine

90% of the time the lugs have snapped on the drive - you can try to glue them back on or a new one is only about £15

If you are unlucky like me, then the actual speedo drive has died and you will need a replacement which is £100+ - best option here is to find someone breaking a Fazer and see if they have the part. I did this and got one for £25