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Discussion Starter · #1 ·
I got a 2002 GSXR 600 mint shape third year owning it only has 20k on it but for some reason every year it burns a stator and rectifier. At first I thought it was cause of the burnt connectors on wire harness side of the plug so I cut it and hard wired it and soldered it up for both the stator and rectifier plugs. Then it ran good and charged for a few months before I started to get issues. After a long ride it wouldn’t start at the gas station but after cooling off it did start. Then the battery would die overnight or if it sat for a day. So I charged the battery went for a couple rides before it ended up dying on me when I was in traffic barely moving just got a backfire and the power cut off. I’m guessing I should buy another stator and rectifier To start with but any ideas what can stop it from just burning another one out?
 

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Are you replacing with genuine, and latest, Suzuki parts?

How old is the battery? What voltage does it read if you disconnect it? Do you know if it is in good condition or something wrong with it (e.g. fused cell, meaning low voltage)?

Could there be a short circuit somewhere else in the 12V system creating an excess load on the alternator? When the battery is disconnected, what is the resistance between the two terminal leads?
 

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Have you ever charged the battery then checked the charging voltage with a voltmeter?
 

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Discussion Starter · #5 ·
Are you replacing with genuine, and latest, Suzuki parts?

How old is the battery? What voltage does it read if you disconnect it? Do you know if it is in good condition or something wrong with it (e.g. fused cell, meaning low voltage)?

Could there be a short circuit somewhere else in the 12V system creating an excess load on the alternator? When the battery is disconnected, what is the resistance between the two terminal leads?
First time I replaced with cheap eBay parts had no luck there then next time around I actually bought real Suzuki parts. The battery isn’t even a year old but I don’t have a volt meter to test it. I believe there is a short somewhere I have found a used wire harness I may try to pick up. Wouldn’t surprise me if mine is burnt between the stator and rectifier because both ends of it at the plugs are in rough shape. If that don’t cure it Maybe I’ll track down an ecu hate to throw money at it
 

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2004 GSXR 600, 1992 GSXR 750, 1983 XN85 Turbo & some Euro bikes
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Maybe I’ll track down an ecu hate to throw money at it
So don’t. A digital volt ohm (DVOM) is way less than the cost of a new part. Cheap as chips (nearly) on Amazon. My guess, if I were to make one is you have a short somewhere in the harness between the R/R and the battery. Check the harness connector where the R/R plugs in and see if the connector is worn through inside.

Digital Multimeter with Case, Fochanc DC AC Voltmeter/Current Meter,Ohm Volt Amp Test Meter,Tests Resistance,Diode,Continuity for Household Outlet with NCV Function - DM002 https://a.co/d/0BnJ5Sf
 

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Discussion Starter · #7 ·
So don’t. A digital volt ohm (DVOM) is way less than the cost of a new part. Cheap as chips (nearly) on Amazon. My guess, if I were to make one is you have a short somewhere in the harness between the R/R and the battery. Check the harness connector where the R/R plugs in and see if the connector is worn through inside.

Digital Multimeter with Case, Fochanc DC AC Voltmeter/Current Meter,Ohm Volt Amp Test Meter,Tests Resistance,Diode,Continuity for Household Outlet with NCV Function - DM002 https://a.co/d/0BnJ5Sf
Ok cool then first step will be a volt meter for that price I should already have one sound like it will make life easier and no guessing games
 

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I'm amazed you have done all this work, changing electrical parts, soldiering wires without checking resistance or continuity. 🙄 Do you have a Workshop Manual ?
With key off , disconnect negative lead. There should be 0 current (Amps or Milliamps) moving between negative (Black) lead and negative Battery terminal.
This will indicate a Short. So since the Negative wire goes straight to Earth, one (or more) wires connected to the Positive (Red) wire is shorting to earth.
Study your wiring diagram and learn where every wire goes.
Check every connector and contact, with a magnifying glass (ECM connector first !) (Check fuses for continuity), clean and brush with Di-electric Grease. (y)
Look for White or Green oxidization.
 

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A weak battery draws more current (hence lowers the voltage sensed by the rectifier), and that makes the rectifier and stator to work even harder to bring the voltage up. Your descriptions of the battery describe symptoms associated with weak battery on its way out.
 

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A weak battery draws more current (hence lowers the voltage sensed by the rectifier), and that makes the rectifier and stator to work even harder to bring the voltage up
This is incorrect when we talking about moto type of generator and shunt type of regulator-rectifier. Lets see.

Moto type of electric generator is the magneto type of generator that use a solid state permanent magnit. This type of generator produces constant power at certain revs. And if nobody consumes this energy than the regulator should shunt the stator windings to reduce output voltage and this will heating of the regulator internals. Opposite this if you turn on many consumers of the energy (or your battery is weak), than output voltage will lowering and regulator have some rest. So lack of the energy consumers turned on at highest revs will be a reason to regulator overheating and burning off.
 

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just went searching on motorcycle stator rectifier regulators, and it seems we're still using 'shunt regulators'.
Yes most of the modern motorbikes have a shunt type regulator. But not all of them. For example, the Honda Gold Wing has an automotive type electric supply system. Its generator has excitation winding and the regulator controls of the excitation current.
 

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I'm sort of shocked that I didn't realise they are shunt regulators and that this is a constant hp drain on the power, even when not needed.

I never really thought about it. Modern electronics there is not actually a need to use a shunt, even with a magneto generator. One can simply build up the voltage from the magneto coils to high voltage in a storage capacitor, which will increase until the capacitor voltage matches the back EMF from the generator, then there is minimal drag on the engine. With high voltage in the capacitor, it can then be down-converted to 14V by rapid switching through a buck converter.

I'm actually a bit shocked it doesn't work like that TBH. Maybe there is a market to replace shunt regulators with 'that' design? Have I just destroyed it as a new patent idea, by mentioning that sort of design? It would be a straight swap with the existing shunt regulator, but would have to limit the capacitor/coil voltage to the known insulation maximum it can handle.
 

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My guess is that the hp loss is inconsequential. I think the gsxr stators are also good for about 350 watts. You are using about 1/2 of that with the battery charged up, lights and engine running, so it is only wasting about a 1/4 hp. Add some more load and the "waste" goes away.

Light, simple and economical wins out.
 
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i think it's a known mod to replace the shunt type regulators with one that is an on demand type one.
The less heat and reduced requirement to mount in a location that has plenty of airflow contributes to the advantages.
Not having the stator run at 100% all the time reduces stator wear as well.

I think Chuckster is the resident expert on this if I recall correctly... do a search for his posts or dm him and see if he'd share his knowledge.
I think they were getting a series regulator from Polaris or something like that.
I think I'm running a switching type regulator with the race alternator but no way I could recommend it... too many issues. At their torque recommendations for the generator flywheel bolt, my flywheel came loose on my first test and stranded me a mile from home. No way to start.
 

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@JCW yes, from that forum I quoted, I hear Polaris with specific item code being mentioned, and that it is made by Shindengen. There are also ways to verify if other custom/aftermarket rectifiers are indeed 'serial' or not.

@QRO agree, really need to thank @XPOH on the noteworthy mention, learning new things everyday

It seems, shunting a 3 phase (stator) supply at high voltage (~45V) is safer than trying to regulate it differently. Cooler weather is a good friend for heat. A serial rectifier, if I read correctly, can take stator inputs up to 75VAC. It seems we should be able to run a mini fridge this way and cool some cans.

Chinese stators are generally 'Y' (whye) connected vs the OE 'delta' connected. There's a way to identify it. I honestly don't remember the one I got, so I shall keep using it. Also, the post recommends

However, note the way to measure stator input to the rectifier while the bike is running, at various RPMs (set using the idle adjuster) is a good way to check things are working, on top of measuring the voltage (DC and AC ripple) at the battery posts. One more thing, he recommends 'Electrosport' stators.
 
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