If the bike is running fine, I'd probably not mess with the beancan until/if you have symptoms indicating you should go in there. On the other hand, if you are planning a big/long trip, say 1000 miles or more, maybe you might want to go in there and just clean things up beforehand as a preventative measure if you have no records of it ever being serviced. As for me, I haven't gone in to mess with it on my bike, and I've been riding it for ~8 years now since I rescued it, and I've ridden it from New Hampshire to Tennessee and back and all over New England area with no issues.