My KLX250sf fuel injection model (14,000 problem free miles) let me down the other day. The battery was flat. I thought I must have left the lights on or something... I charged up the battery and all was fine. BUT yesterday I went into the garage and out of curiosity turned on the ignition. It was OK, so just turned it OFF again. About 10 seconds later I heard a whine start from the bike. I waited to see if it would stop. It did not. It took two ignition ON/OFF cycles to knock it off. I now think the fuel pump constantly running was what drained my battery, but I have no real idea what might be causing it. Any theories on this one?

 

Usually there will be a relay to control power to the pump. I don't know its location on the FI bikes but it sounds like it may be sticking from time to time. Locate the relay and see if the stuck fuel pump sound stops if you tap on the relay. That may help you to isolate the problem.