Mine did that and I didn't do any disassembly, just shot the key hole full of WD40. I also shot the plastic mechanisms with silicon spray. It worked *but* WD isn't the best thing for the key & tumblers. It eventually sets up so you have to repeat at least once a year. A graphite lubricant is probably best for the lock itself. It's what locksmiths use.
2014 Ninja w/bags, Motowerks lowered pegs, Seth Lamm Seat, Puig screen, Givi XS307 tank bag, WOLO BadBoy horn, LEDPerf H7C HID lights, Aerostitch Roadcrafter