I have a 2009 Hyosung 250 and I've had this problem for as long as I've had the bike and through numerous batteries. I just purchased a new battery a few days ago and it checks out good puts out 12V. My bike will not cold start without being jumped/hooked to a tender. Turn the key, dash lights up everything looks good, press the starter and you hear a slight click but no crank. Hook up to a tender and it starts immediately. The bike, however, will start if it was recently ridden within an hour or so. I don't know what to do but I need to fix this issue. I can't take my bike out except for a round trip no stop without fear that I will end up stranded somewhere. Please help.
Because the bike starts when jumped or when the restart is immediately after riding, we know that the battery is being charged by the bike's alternator, and that the starting system (starter motor and its wiring and controls) is operating correctly. Because the bike runs OK, the ignition system (spark plug, coils, high tension wiring) is also operating correctly.
Make sure to turn the motor off using the ignition switch, not the motor kill switch. On many bikes, the kill switch allows the lights and parts of the ignition system to continue to use electricity. If you use the kill switch regularly to stop the motor (as is sometime recommended because you can stop the motor without removing your hands from the grips), then remember to turn the ignition switch to "off" after you do so.
If you are turning the ignition switch off, the symptoms you report indicate the bike has a wiring or switch fault that allows electricity to flow from the battery even when the ignition switch is turned off. With a little time, the bike's battery discharges and is thereafter unable to start the motor.
This can occur because a wire's insulation has worn, and is shorting the copper conductor to another metal part, or because a electrical switch or relay or other electricity user has developed a short or other fault.
Physical examination of the bike, and basic electrical troubleshooting, should reveal the source of this electricity consumption. If this is something you're not comfortable doing, then you'll have to find a competent mechanic to address it.
This sounds like two things to me : a problem of the starter relay or a problem of the starter itself. If you can find it on your bike, check the voltage getting in and out of the relay when the starter button is pressed. If you have ~12v input but nothing output, the relay is not working. If you have ~12v output, and ~12V to the starter motor too, then you probably have "sticky starter motor", meaning the graphite contact are worn out or dusty and can get the current to the motor's collector.
First thing would be to check the tension around these two, that should give you a good start.
Check your spark plugs to see if they are fouled-up. also try starting the bike in the night when its dark and see if there is any arcing ( plug leads/ wiring ) your coils may be defective (weak)