As Steell said, those car-jumper chargers can damage the reg/rec on the bike. Same goes for a running car for jumping.
For jumping a bike, you should only use a battery, and that only from a stand-alone 12v battery or from a vehicle that is not running.
Cars can jump each other while running because they use a different type of charging system from most bikes. They are not harmed from running-jumps.
15.4v is higher than I would expect. That can be one of two problems. Either the regulator/rectifier is now shot, or the voltage is low to the regulator.
The voltage regulator measures voltage through the brown wire. If there is resistance in the fuses or ignition switch, the brown wire can have low voltage on it. That makes the regulator raise the voltage to the battery. The fix is to clean the connections and contacts for the fuse holders and ignition switch (and any other connector with the brown wire). This is a big job, though.
If you need a regulator/rectifier, you should be able to use any KZ reg/rec with 3-yellows, 1-brown, 1-black, and 1-red/white wire.
Post edited by: loudhvx, at: 2007/12/14 17:18