i dont understand why though? can you explain? when i jump cars i leave the jumper running - whats the difference for bikes if they run on the same circuit. **edit, quick google search confirms my thinking also.... http://www.advrider.com/forums/showthread.php?t=66214 http://forum.svrider.com/showthread.php?t=110361 sounds like the issue arises if the cables are left on for too long - and not necessarily from having them hooked up assuming the bikes electircal system was in proper working condition beforehand, it would only take the amps it needed and burn off the rest as heat - hence there being a problem if the cables are left connected for too long and burn up the R/R what happened to replacing weak batteries before trying to diagnose other electrical system problems? if you KNOW the battery is weak, and youre having starting problems, it makes sense to start with replacing the battery