Intermittent Performance

[TedMosher]

Charging... Except not...

Well, the bike is running awesome, except alittle clutch slippage (have new disks to install) and charging. I tested the generator its doing fine. When I take the bike for alittle spin its actually discharging the battery? Whats the best method for testing the voltage regulator. I should also mention, when the bike last broke down, the battery was spewing acid from over charging. Anyone have any directive tips?

[cywelchjr]

For the charging, first thing to do it to actually measure the voltage of the resting battery (should be about 12ish), then start the bike and measure voltage again (hopefully still about 12ish), then rev the engine to about 3500and check the voltage again (should be 14ish). If the first 2 are low then you need to charge the batter or may have a bad battery. if the last one is pretty much at the same as the second measure then I would first say to check the large white connector behind the fuse panel, it gets dirty and melts, 97% of the time that is the problem.

And the rest of the time it's something else.

Sorry, just had to do it. Anywho, Nate is correct, check the voltages and if they are good your probably fine, if not then check that connector FIRST, if it's good then your into getting deeper into the system when you get back from your trip. We can help you get through it, there are more than one of us who have troubleshot charging issues with some measure of success.

[cywelchjr]

Well, the bike is running awesome, except alittle clutch slippage (have new disks to install) and charging. I tested the generator its doing fine. When I take the bike for alittle spin its actually discharging the battery? Whats the best method for testing the voltage regulator. I should also mention, when the bike last broke down, the battery was spewing acid from over charging. Anyone have any directive tips?

Over voltage will harm the battery just as quickly and badly (if not worse) than under charging. Do the voltage checks, then with the numbers in hand it's time to go to the next steps, while not common, it's certainly possible to have a regulator fail in the full charge position rather than the no charge position like normal, just not very common. It's also possible to have a wire get pinched and cause it to appear to be that issue, and if the charging voltage is high, tracing all of the wires in the charging circuit would probably be in order.

[TedMosher]

The Connector

The plug coming from the generator/alternator is in good shape. I just replaced the generator in trying to chase down this issue. While the new generator is in better shape than my last one, it wasn't the source of the problem.

[natemoen]

what were the results of the battery voltage tests?

[TedMosher]

battery is 12.75 volts, drops when the bike starts. I have a switch to turn my headlight on and off, with the light on it drops another .4 volts. When I rev the engine the voltage slowly goes down.

[natemoen]

What does it drop to when you start it? What is the voltage when you rev the engine up to at least 3g?

[TedMosher]

12.52 off
12.02 on
& 3500+ 12.02 and dropping

[cywelchjr]

Ok, now you need to run through the tests which are in the service manual to determine if it's the field coil, bad stator windings (just cause you replaced them doesn't mean they were good if you didn't check them first) or the reg/rect unit. The reg/rect is the most often failed part of the system after the connector, but you need to go through the tests to confirm, and if the tests confirm the reg/rect you need to decide if your going to get a new OEM unit, and Geezer unit (which there might be a wait for as he is under the weather right now) or take a chance on the used unit form ebay or other used source (I did the ebay deal and got lucky, but it only cost me $15 with like $6 shipping so it was worth the gamble).

[TedMosher]

resistance between stator phase wires is .5, .5, .5 - .6
resistance between coil wire is 3.6

[cywelchjr]

resistance between stator phase wires is .5, .5, .5 - .6
resistance between coil wire is 3.6

Those values are within spec. So next check is the reg/rect. The test is in the service manual towards the end, and describes how to test, it requires disconnecting it and then you test the diodes, you likely will find one or more diodes bad, in which case it will need to be replaced, but there is a test I believe in the tech tips where you ground one of the field coil wires with the bike running and (assuming it's the reg portion of the reg/rect that bad, not the rect portion) and if the voltage comes up it the reg that's bad.

Here is one test for the reg from the tech tips. http://www.xs11.com/xs11-info/tech-t...regulator.html

[TedMosher]

Yeah, most of my diodes appear to be toasted, thanks for the help guys. Appreciate all your input and experience!

[natemoen]

What diodes are you talking about?

[TedMosher]

Just did the test you linked, my tach works! And when I rev the engine the volts go up! So my regulator is bad, which sucks, but its nice to know I found my problem.