Anybody ever heard of this?  Started doing it right after I bought the bike.  Just occasionally at first, but now it's 99% of the time. 

It would be nice to know how fast my motor is spinning when I get above 6,500 RPM.

i have heard of tacs doing this but usually its when someone had it set to the wrong number of cylinders....  not really your issue here.  but low battery voltage can mess with the electronics or its not getting a good signal?  sry i dont know enough about the bikes wiring to offer more.  but i did have a bike screw up with speedo and tach because the computer didnt get enough voltage when starting up.

can't say for certain about the double rpm thing, but I can suggest you check the black/yellow ground connection on the front bolt holding the left hand (#1-4) coil to the frame, up under the tank. This wire has a tendancy to flex, and break strands at the terminal lug, and WILL have the effect of poor tach performance, and downstream a "no start" condition.

can't say for certain about the double rpm thing, but I can suggest you check the black/yellow ground connection on the front bolt holding the left hand (#1-4) coil to the frame, up under the tank. This wire has a tendancy to flex, and break strands at the terminal lug, and WILL have the effect of poor tach performance, and downstream a "no start" condition.

I'll check it, thanks!