Battery depleting while on interstate

[Cragdog]

So I rode the 550 to work today, got me there no problems, didn't notice anything wrong, but when I left work and was riding down the freeway for a few miles the bike started loosing power, sounded like it dropped a cylinder and I knew something was wrong.. Thankfully I was able to navigate my way through traffic and get to the other side of the congested freeway. Once I stopped I noticed my lights were very dim. Any ideas why my battery would lose power while operating normally? Regulator or rectifier problems perhaps? Or maybe the alternator?
Damn.. Thought I had sorted out all those electrical gremlins!

[Cragdog]

Not the best place to have bike problems..

[tz375]

Yes, all the above.

It could also be a faulty battery, broken wire or crappy connections.

I'd start off by charging teh battery - assuming you got it home - and then test the battery voltage:
With bike off
Then with it turned ON but not running
Running at low revs
Running at say 3500-400 rpms

See what that shows up. Is it charging, is the battery dead? Take it from there

[Fritz500]

I had issues with my T500 battery. It charged OK then would die over time. Turned out the voltage regulator was faulty after 40 odd years!!! Popped a second hand one in and no troubles since.

[Alan H]

Could be anything from a bad connection to worn genny brushes.
Like tz says, start with a battery check and then does it charge.
Make sure there's acid/water in all the battery cells.

[tz375]

I just had another look at the picture and the wiring looks a little less than MIL grade. What is going on with that rear lamp? It looks as if there are loose wires. Are any of them carrying power?

Even if they are not the problem I would tidy that up.

[Cragdog]

Thanks for the replies guys. Freeway service patrol guy stopped and gave me a jump, that boosted my battery enough to start it up again and at least ride it off to the next exit where I waited for my friend to meet me with my truck.
I didn't have the time to look more into it last night, but I'm thinking after work today I should be able to at least do some battery testing.
I know my alt brushes are good because I have like 4 sets of alternators and chose the one with the brushes in the best state. (Although, I have the Kokusan system in there now and should install the ND since I have almost all the parts except for the points plate.) My battery has been good and was new a few months ago, it's full of acid in all cells and holds a good charge for the most part. This happened once before to a lesser degree a few weeks ago, but the battery seemed to "bounce-back" after a few minutes of turning the ignition off then I was able to ride away fine..
Tonight I will do the battery testing with different states of load and record the results.

I just had another look at the picture and the wiring looks a little less than MIL grade. What is going on with that rear lamp? It looks as if there are loose wires. Are any of them carrying power?

Even if they are not the problem I would tidy that up.

The taillight is cheap Chinese crap.. The colors don't match but it's wired up correctly, those loose wires (yellow & black) are for my rear turn signals which I haven't hooked up to the rest of the loom yet. (The rear TS are the only thing not wired into the loom at this point). So far I've just been running the headlight and that cheap-o taillight.

[pearljam724]

Remove the rectifier, turn it over to check that one of the terminals aren't burnt. There's approximately six to eight of them. Not the connection terminals. The terminals I speak of should be coated with a protective coating. Looks like a bad place, for the bike to leave you stranded. When riding, Id put a rag or something in between the battery and the seat pan. It's very possible to arch both posts. Suzuki originally, installed a plastic piece to cover those posts. Which you do not have. Looks very similar to this. http://www.ebay.com/itm/NOS-Honda-Motor ... 0c&vxp=mtr" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false; What did you do to get the bike home ? I saw on TV last night, that the average Los Angeles resident spends 64 hours a week in dreadlock traffic. Screw that, there's nothing out there worth putting up with that every day.

[Cragdog]

Yeah the traffic seriously sucks during prime commuting hours.. That's why riding a motorcycle is a huge advantage in CA also tho, because we are the only state that allows motorcyclists to split lanes. So when cars are stuck in traffic, I just move over to the far left lane and cruise past everyone!

I have a truck so my buddy stopped by my house and drove it to where I was, we loaded up the bike and were back home in a snap.

[Cragdog]

Battery test results:

Before charge (after getting it back home): 12.1v (see how it "bounced-back")
After charge (5hr 2amp): 13.0v
IGN ON Engine OFF: 12.4v
IGN ON Lights ON Engine OFF: 12.1v
Engine 2k RPM: 12.2v often drop to 7.5v or even 0.00v
Engine 3.5k RPM: 12.1v but jumping all over the range, 3.5v, 4.2v,11.0v, 9.8v, etc.
Lights were OFF for the above 2 tests, when lights flipped ON with engine ON about a 0.3v-0.4v drop observed.

After all tests and adjusting the timing (~30min idling): 11.9v (everything OFF)


I didn't end up testing my reg/rect or alt. because I was tired of my bogging-out while at idle, so instead i messed with the carbs until I got it to hold a steady idle around 1,200 RPM. Now that that is taken care of however I will get to the other tests either tonight or tomorrow.

You can tell from the above numbers that there is a slow, but steady drop-off of power the longer the bike remains running. If it runs long enough to the point where the battery is at only about 10.8v that's when you start the notice a loss of engine power and a little more below that it will drop a cylinder and die. Obviously the above measurements with engine running should be somewhere in the 13.5v-14.5v range, but because my battery is "bouncing-back" so to speak, I am fairly confident my battery isn't the culprit but rather the regulator and/or rectifier, and less likely the alt., but that will be checked as well regardless.

[tz375]

So that means there is no charge at all going on and an intermittent dead short.

Start with the easy things like turn it off and disconnect the battery and test for continuity in each line first and then check the alternator rotor and stator and after that try a new solid state regulator/rectifier.

[jabcb]

Are you measuring the voltage at the battery terminals?
Are you starting the bike with the electric starter?

Let us know how your additional tests go.

[Cragdog]

Are you measuring the voltage at the battery terminals?
Are you starting the bike with the electric starter?

Let us know how your additional tests go.

Yes voltage was being measured across battery terminals.
Electric starter hasn't worked since I've had it, so kick only at the moment.

[Cragdog]

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... ink:top:en

Wow, this price looks too good to be true, but then again it is coming from China... The description sounds promising however.
Combined voltage regulator / rectifier direct replacement for Suzuki GT triples.

[tz375]

After you check the wiring for continuity, set your multimeter to AC and test across the yellow leads for AC voltage - should be 20-60v across that when running.

if that's a bust, check the voltage (DC) between the green lead and ground. That should show battery voltage or maybe 0.5v less. If there's nothing there with the bike running, it's 100% a shot regulator. Get one from ebay or Oregon motorcycle electrics and try again.

The regulator on a GT changes the amount of power going to the electro magnet (field coil). If contacts are crappy inside that unit or the unit is damaged internally, power will not flow. That said, check that the orange lead to the regulator is carrying 12v. if there's a problem in that supply, even a good regulator will be unable to function.

If the orange at the regulator is dead with the motor running, run a temporary lead from the battery + to that connector on the regulator and see if it starts charging and if so test it at idle and 3-4k. Don't leave that test lead in place after you shut off the bike and don't run it that way for any length of time because you will damage parts or worse.