Get some ACF50.I use it all over the bike.Seems costly but goes a long way,
http://www.ebay.co.uk/itm/ACF-50-Ant...cAAOSwPCVX4l2B
Great lube and anti-corrosion treatment.I also use it in and on all my electrical connectors/bulb holders etc as well as the hinges and locks on my fuel cap/ignition.
If you don't know what it is read here,
http://www.acf-50.co.uk/motorcycle.htm
HTH