Advice needed please
 

I have been getting my trackbike ready for next weekend today, i put the battery back on and fired it up for the first time in about 4 months.
It doesn't have an ignition switch anymore, it runs off the kill switch.
I connected the battery leads and waited for the tacho to go through the normal sequence of running all the way round the clock and back to zero before hitting the button, it didn't do this though, it went half way round and stayed there for a few seconds then back to zero.
Despite this, the bike fired up and runs perfect, and the tacho works as it should...
But now when the ignition is switched on, the tacho needle doesn't move at all, but works when the engine is running...
Is there a reason for this ?
ALso, when the ignition is turned on and the fuel pump whirs as it primes, the whirring carries on when the engine is running, i know the pump still has to run, but normally i can't hear it, would this be related to the tacho issue ?
Any advice would be appreciated