Just looking to narrow a problem with a friends 2011 900 Classic LT. The FI light has been on for a while I guess and she's just telling me about it on a poker run. So here what I got...The FI lights on and it seems like it's missing off the back cylinder. It has 6000 miles on the bike and the first thing I'm thinking is the rear plug is bad but will a bad plug set out the FI light or do you think it's a vacuum line off? I use to have a 900 and never had this problem, I just wanted some opinions on what it could be before I tear into it, she does have new plugs so I'm changing them regardless the problem.