I have read somewhere about leaving the kill switch down makes the battery run flat quicker while the bike is parked. Is this true, why? I have no problems but want to know if its important.
While the kill switch is down the bikes electronics are trying to "hunt down" the signal from the ignition key. The process is similar to a mobile phone when it isn't receiving a mobile signal, the battery runs down faster because it is using more power searching for a signal. It will take a while but it will go flat quicker than leaving the switch up.
To be clear, the switch has 3 positions. up, middle and bottom. It is the bottom position that causes the problem. You should not be able to leave the switch in the bottom position as it is spring loaded. There is a problem with some switches that do not spring back to the middle position. If the switch does stick at the bottom, then you will get a warning on the dash telling you (need an ECU update if not manufactured this year)