Yet another S3 starting problem

[Neek]

Hey guys, I have an 03 S3 w/ stock charging system. Replaced the battery under a year ago. Now the battery loses charge easily and if I don't keep it tendered, it doesn't seem to hold enough charge to start the bike after a few rides.

1. Can you point me in the direction of the proper method to inspect the charging system with a multimeter and what I should be looking for. Keep in mind I am a total electrical idiot.
2. If the system needs replacing/upgrading what have been the systems used with success for you?

Thanks in advance.

[Duckeater]

Look for a bad stator. There are numerous threads about that, and Speed3's are notorious for burning out stators. I had to get a new one recently on my '08.

[Neek]

Yup got that...but can you point me to a resource as to the proper way to diagnose the charging system. I have a multimeter but as I said above...I'm an electrical idiot.

[Jaket]

first.
Start the bike. Measure the battery voltage with multimeter(DC volt) before you starts, Then measure when it runs.. You should see something like 12.5 volts before ignition is on. It probably drops to 12 or below when ignition is on. When it runs, it needs to be 14 volts or so. But it could be 13.9 . Then increase the revs and see how it changes. Usually in speedy it drops. This could be because the wiring is little undersized. There is another thread about the mods to increase the voltage.

If the loading voltage is not there. You can take follow the cable from the left side cover. it goes behind the cylinder block. Unplug it and measure the cable going to the engine. Every wire against the ground should have very high or infinite resistance(ohm area in meter). And every cable pair should have very low resistance value. You have three wires, so measure between every one of those, and everyone should be very low against each other. if something is different, the generator coils is bust.

[Duckeater]

Not really, because I am an electrical idiot too, but I did notice that I had enough battery power (new battery - same as you) to run all of the indicators and get the starter running, just not enough to turn the motor over. When I had it on the tender and fully charged it would start the bike, but after riding it for half hour or more and shutting it down then trying to restart, it wouldn't start. This tells me that whatever part of the charging system that is responsible for charging the battery while the bike is running (alternator/stator) is failing.

That's the best I can do, but there are lots of really good mechanics on this forum that will likely chime in, or you might find a thread with the info you are looking for. Good luck!

[crashmasterd]

...but there are lots of really good mechanics on this forum that will likely chime in...

Jacket's writeup is a pretty good starting place. Also, check for melted or burnt wires on/around the regulator. You might pull the stator cover off and look for burnt wires too. This doesn't require any electrical expertise, just a socket wrench and a gasket. It'll be obvious.

There's a writeup on a regulator and wiring upgrade around here somewhere. Always something to consider.

[Joe Houle]

to just check for an even voltage spread on the stator, no need to pull the cover.

[Neek]

Well did some testing this morning. I have a flowchart that describes proper charging system testing and the first thing it says to do is check at 2500 rpm and see if it was above 13.5, which it was, then rev it to 5000 rpm and see if it was below 14.8, which it was. Supposedly that means the charging system is fine. When I did replace the battery a year ago I went with a cheaper knockoff "Adventure Power" battery. Has anyone reported issues with them not holdling much charge after a year? I'm considering buying a proper Yuasa.

[Jaket]

Yuasa is superior battery. It just kicks out more starting current. One friend had major problems with harley starting. With yuasa it works. I have heard lot of similar stories.

[speedybadge]

I would say its your battery neek, look at the recent post i have put on and you will see that after all the testing, it was the bloody battery that was at fault.