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**Steve** · 07-21-2007, 08:32 PM

Instead of "leave the bike running all day...", why not just put a voltmeter across the battery and know for sure?

Even a new battery will go dead if it is not being charged.

You say "once the bike is running it runs fine with no problems at all". What does it take to get it running?
Do you have to charge the battery overnight or jump-start it to get the bike running? These could be BIG clues. So...I am not going to scream out "STATOR REGULATOR/RECTIFIER". I am only going to scream REGULATOR/RECTIFIER.

You say you have done all the tests in the Stator Papers, this implies that you have a meter. Use it, check your charging voltage and KNOW FOR SURE. :shock:

.

**twistedwankel** · 07-21-2007, 09:30 PM

Originally posted by igotcenter View Post

, all lights work fine, high/low beam, signals tail, Nothing seems to be lacking any power at all. I could leave the bike running all day but the second i shut it off, It stays off. and yes it is a brand new battery. ive run through the Stator paper tests and the stator seems to pass with flying colors. i have yet to test the R/R

It is an aftermarket R/R but why on earth does it run so well if the stator/rr were at fault would the bike just drain the battery and die?

Like i mean this bike runs like a top!!! it runs better than alot of my friends bikes, onlything is if i sut it off it don't run no more.....
Gary

If the battery is still full up 13Volts, lights bright I would expect the starter to at least engage and "drag" while trying to start it making the headlight dim. If the head light is still bright. - Check out the solenoid and on/off kill switch along with the clutch safety switch. Might be dirty. The lights kill the battery if it's not charging - not the ignition system. Yes it will run all day until you kill the battery with the lights.

Do the stator and RR tests again with the bike running.

**earlfor** · 07-21-2007, 09:37 PM

The charging system on the GS's is super, super simple. There is a battery, a stator and a rectifier. The first thing to always do is remove and charge the battery and let it sit for 8 hours after fully charging to be certain it will hold a charge. The next step is check the stator AC output voltage (with the stator all 3 yellow wires simultaneously disconnected from the R/R) on each of the three legs. It should be 80 volts AC at 5000 rpm. If you have 80 volts, the stator is fine. That leaves the R/R for being the component at fault. At this point, dont bother checking any further, the R/R is faulty, replace it!

A note about voltage and the R/R...............
The bike's electrical system, in normal running, lights on, etc, consumes aproximately 15 amps. You must have a minimum of 15 amps in the electrical system for the bike to be self sufficient electrically. Each stator leg is in a different 80 volt AC phase. Each phase contributes aproximately 8 amps of flow to the charging system through the rectifier. The R/R has three rectifer circuits, one for each stator leg. All circuits produce 12 volts and aproximately 8 amps. Add DC voltage together (three 12v lines) and you still have 12 volts, but you have triple the capacity. The electrical system is aproximately at equilibrium with two of the three rectifier circuits working. The headlight is normally on the 3rd leg, and when it is turned off, that circuit/leg is inactive. So, you can see that if you have one rectifier circuit burned out in the R/R and are running the headlight, you will drain the battery. Now, when you try to start the bike, you press the electric starter, the starter solenoid kicks in and the starter grabs for 50 amps from the battery. If your battery is in a drained state, the sudden 50 amp draw will pull the battery voltage down to nearly nothing. The ignition system will not function if voltage to it is below about 11 volts. So you cannot start the bike with the starter if the battery is in poor condition or drained. Push starting the bike removes that 50 amp starter draw.

Also, since all rectified internal DC output circuits in the R/R produce 12 volts, checking voltage on the red and black DC output wires will not tell you if one of them is faulty. If the battery is in good condition and the stator is up to spec, it is amperage the R/R is not producing.

Bottom line. .............replace the R/R. Trust me. :-)

Earl

**robertbarr** · 07-22-2007, 12:03 AM

Originally posted by earlfor View Post

At this point, dont bother checking any further, the R/R is faulty, replace it!

Trust me. :-)

Earl

You know, I was wondering. What if the main fuse were dead (open) and the OP gave the bike a good healthy bump start? The alternator could possibly cough up enough output to power the ignition & lights, and it wouldn't have any connection to the battery at all.

The ignition would have to be switched on when it's bumped.

I would almost need an '850 of the same year to test this, but it would explain the symptoms.

**earlfor** · 07-22-2007, 01:21 AM

I dont think so. The bike runs on DC voltage. Assuming no battery voltage, but continuity to ground, it would have to run on rectified AC to DC. Since the stator output is directly proportional to rpm, and if we have 80 volts per AC phase at 5k rpm, then at start up rpm, voltage would be proportionately less. Assuming on a bump start you could get the electrical output of an initial 500 rpm, then amperage available will be 1/10 of max rated (24 amps), or about 2.4 amps and that is not enough to run the bike.

But hey, I could be wrong. :-)

Earl

Originally posted by robertbarr View Post

You know, I was wondering. What if the main fuse were dead (open) and the OP gave the bike a good healthy bump start? The alternator could possibly cough up enough output to power the ignition & lights, and it wouldn't have any connection to the battery at all.

The ignition would have to be switched on when it's bumped.

I would almost need an '850 of the same year to test this, but it would explain the symptoms.

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