Tach sometimes goes away under acceleration

I have only noticed it when I was in a high gear (i.e. 4, 5 or 6) at about 7000 RPMs and then I hammer the throttle without down shifting. It moves about 500 RPM and the it flatlines to 0. The bike never misses a beat and continues to accelerate normally. Then, usually about 10,000 RPM or so it springs back to life. I have had some ideas presented but I would much appreciate the input from the forum members.:bow Thanks! :confused:

I have only noticed it when I was in a high gear (i.e. 4, 5 or 6) at about 7000 RPMs and then I hammer the throttle without down shifting. It moves about 500 RPM and the it flatlines to 0. The bike never misses a beat and continues to accelerate normally. Then, usually about 10,000 RPM or so it springs back to life. I have had some ideas presented but I would much appreciate the input from the forum members.:bow Thanks! :confused: Check loom connection to clocks and apply dielectric grease. Do the same with the big white connector behind LHS headlight (Under carbon infill). Probably corroded/dirty connections.

This used to happen to me. Turned out to be a loose ground (in my case at the negative battery terminal) but could be anywhere - like William YZF-R1 said check the loom for bad connections. I would check the battery connections first as they are easy to get to.

Thanks for all the good info. I will be checking every suggestion starting with the battery. I am installing a Tender-Plus this weekend. :thumbup