I am going to try and explain this the best I can without taking up too much space.

I have 2003 600rr that I have only had about 8 months, when I bought the bike I replaced the battery.
Now 7 months after I replaced the battery I took a trip to the bank(15 min away), hit the kill switch and went through the drive through. Three or four minutes later when I went to restart the bike I had NO juice, barely enough to crank it once or twice but not enough to start it. I had a friend jump the bike and rode back home. I went out like 20 min later to see if it would start and it started fine, turned it off. I took it to the gas station, got gas and restarted it. To make this short I turned it off and on mulitple times with NO problems. I then rode to a friends house (40 min away). I parked it and tried to restart it right away(to change parking spots) and it had NO juice. Four hours later it restarted with no problems and not needing a jump. I took the bike to the battery store and they tested the electrical system, here are the results. (This is after the battery sat on a trickle charger all night)

Battery had 12.1 Volts
There were 4 volts of starter draw which brought the battery down to 8.1 volts or so
The "alternator" reported a "bad diode"

I'm not sure what all that means or what my options are or where to start diagnosing the problem. Please help

 

My first suggestion would be to check at the battery while the bike is running. It should see around 14 volts around 2500 rpms. if it doesnt, then your stator or rectifier may be on its way out. You can check your stator by accessing the three wires coming from your left side engine cover. Unplug these at there connection...(rectifier) and test across all three leads. I'm not sure of the ohms on that bike, but they should be around .6 or so. the important thing is that they are all the same. If you have one that is off by more than .2, the stator is bad. If they are all the same, I would suggest checking into the rectifier. I'm not sure ofa test for these. These are usually replaced by process of elimination.. if everything else checks out, they replace the rectifier.

I'm not sure how to read the results you got. If their check wasnt motorcyle specific, it might givea false reading. Motorcycles output is far less than most cars.

But, the symptoms sound like a bad battery to me. the terminals can become broken internally and you will have an intermitten condition like this. Also, the battery may have a bad cell which can also lead to this. If it truly was the stator, it wouldnt start 4 hours later. Bad battery, or bad connection somewhere.

 

That is what my first thought was, but when i took it to the shop where i bought the battery (batteries plus) they said it was probably something else. I'm going to take it by the motorcycle dealership on thursday and see what they say. is it pretty easy to take off that left side cover? Im pretty mechanically handy when it comes to cars but i have done little with motorcycles.

Thank you for the input, that is hopefully really helpful!!! This forum is awesome!

 

If you are talking about the side plastics,there are not too bad. One important thing to do is take a blanket or large towel and lay in down on the ground under the plastic and outward to the left of the bike. that way, when you do get it down, the plastic can lay on that instead of the pavement or dirt.. they scratch easily. the hardest part is going to be the darts on the inside of the plastics just behind the front tire. you need to pull the little tabs out and then the entire dart will come out. You should only have to drop the upper part of the plastic, dont bother with removing it from the other side as they are connected at the bottom. Just let the plastic lay on the blanket.

If your talking about the stator cover.. that doesnt get removed. Follow the wires from the stator cover..(should be a set of wires towards the top of the cover)and they will lead to your rectifier. Unplug it at the rectifier and test the leads at that point.

I would still consider the battery or a bad connection somewhere on the bike. A stator or rectifier won't give you the problems your having with the intermitten starting. I would save those as a last resort.

Follow your cables to your bike and make sure you have a good chassis ground and the positive cable is attached well. Also, check for any kinks or breaks in the cables themselves.