So three days ago my bike which runs great and usually starts first time decided to play up.

Key in, ignition on, pressed the starter and the motor starts turning. Turns over and it sounds like the battery is slowly dying. So lights off, wait 2 minutes to let the battery recover somewhat. Checked that the emergency switch is on run and quick scan over side stand switch. All appears normal so I hit the igniter again and the same thing happens. I work the throttle a touch and give up when the starter stops rotating and the relays going mental.

Now I was by myself and my first thought was 'f*ck, ive never bumped a 600 before'. I remember the days of bump starting 250 motorcross bikes and they were a nightmare. Flashbacks of a bump start gone wrong put the fear in me. After doing it everytime I want to ride now Ive got to admit the cbr is soooo easy to bump start. Even dead cold I can get her started within 10 meters on a flat road.

Now I thought It was a flat battery but on the way home tonight I put on the heated grips which draw a fair 2.8ish amps. I expected when I turned the ignition off at the petrol station the controller would automatically cut out due to a low voltage. But no, the heated grips kept cooking for a good minute before I turned them off myself.

I took a meter to the battery once I got home and she read the usual 11.20V. I tried to fire up the bike and it sounded as if the battery was dead. Im not to electrically minded but I suspect theres a earth fault in the starting system. I know the starter motor draws a high current when starting and a leak would increase it even more to the point a fuse blew, but all the fuses are fine.

Any idea's?

 

11.2v sounds low actually. Something drawing power constantly on your bike?

 

Everytime Ive had the fairings off Ive checked the voltage and its always sat around 11.2V - 11.5V. After a good charge like its getting just now It'll read around 13V but I know after a days riding it'll be back down to 11.2V~. Its never been an issue as the bike usually starts first try. I run heated grips nearly everywhere I go but the automatic cut off kicks in when I get off the motorway and into slow city traffic.

Since its the holidays the bike sat for 3 days and it was no trouble to start when I hit town. Which tells me its not the battery leaking to ground.

Just checked the current levels with the ignition on. With all lights off, sidestand up. Basically I only had the oil and neutral light on. With the killswitch at off It read 490mA and with it on run it read 560mA. I dont know what to make of it as I dont have a wiring diagram for a F2. Ill go google it and have a scan over it.

 

I think its a dead battery. a good working battery should read 12.8v or somewhere around that. below 12 when its not running usually means its going out and is gonna die soon. i had a similar problem and thought it was other things. but it ended up just being the battery. i had 12v but when i went to start it dropped down to 4. thats probably whats happening to your battery. bump starting is only a temporary solution. it can put alot of strain on the alternator trying to charge a dead battery and could leave you with a huge bill in the end. hope ya solve it

 

Hope its not the battery coming to an end! If so...

I wonder if a Harleys battery would fit in my bike...