This past friday I left my keys in the bike while at work. The battery completely discharged. I took the battery home and charged it. On sunday I re-installed the original battery and the bike would turn-over no problem but wouldn't fire up. Checked to make sure kill switch was not engaged, clutch in, choke halfway. Did it in 1st gear and neutral. Kickstand up and down. No dice. When I turn the key the fuel injection sound IS present. I then got the original battery tested (its 8 months old btw) and was told it was no good. Note: R/R replaced about 8 months ago. Which brings me to today. I purchased a new battery, got it charged up and I'm having the exact same problem. Bike will turn over, fuel injection normal but will not fire up. I'm thinking the only things that could be wrong are the spark plug, but nothing else comes to mind. Fuel level is around 4 bars. The only maintenance I do myself is an oil change. Anything above that is rocket science to me. Thanks for your help.