Having now put my bike back together after my off at Brands I took it out for a spin on Saturday afternoon with a mate of mine. My battery was pretty flat, even after charging it for the afternoon, so we had to give the bike a bump start. It still wouldn't fire up even then so another hour on the charger, another bump start and it eventually decided to play ball
Anyway, when it initially started the rev counter was going nuts. Shooting randomly up to 7k on tickover and right off the scale with only a whiff of throttle.
But after leaving the bike ticking over for about 10 minutes the rev counter returned to normal, and worked fine for the rest of the day. Was it something to do with the low power in the battery? Or will the rev counter go nuts again and need replacing?