I rode the bike to and from college, never down, maintained very well. One morning(after riding into the garage the night before) I rolled it out of the garage and it would not fire. Turns over fine. Is getting fuel and spark.Talked to local shop, they said battery. Replaced that and used a trickle charger. Still won't start. Brought bike to a shop, they initially thought it was a starter problem, but then did a leakdown test and found various low compressions on all 4 cylinders. I realize the number of problems it could be, but what is most likely? I want to rule out bad rings(because it is maintained and had no previous symptoms for that). I think it is something in the top end. Any suggestions are greatly appreciated.