This morning I turned on my 2010 XT660Z's ignition. As it was doing its pre start check, tach. needle sweep etc. a loose negative battery connection cut the power and all went dark. Two minutes later, connection snugged, started it up again and noticed that my tach. needle was at 4,500 rpm while idling, but that the engine was idling as normal. I shut down the engine and the needle came to rest at 3,000 rpm. Turned ignition off and on again and the needle did its normal sweep, from 3,000 to off the chart, started it up again and needle shows 4,500 rpm at idle. I went for a spin and the needle is consistently showing 3,000 rpm high. Has anyone any idea what might have caused this, and how it can be "re-set" or fixed. It looks like whatever drives the tach jumped a tooth or something. Very odd.

Thanks, Rich.