Rev counter gremlin

[sid]

Hello all, I'm new to the forum, just purchased a 2005 fazer 1000 and I have encountered a problem with the rev counter. With bike on centre stand and running from cold for the first 5 minutes the rev counter needle bounces up and down from 0 to 8000 rpm approx and back to 0 repeatedly, actual revs remain steady. Does anyone have any ideas what the issue might be or indeed have come across the problem and know of a fix.?


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