Charging Challenge - WOW

[Anonymous]

Ok... so here it is, hopfully SOMEBODY can shed some light on this...

The bike (85 gs700esf) isn't charging.

Rewired and checked the stator output wires directly to the regulator.
Rewired and checked the ground direct to the battery.
Rewired and checked the power out directly to the battery.
The Reg passed the flow chart test in the "garage" area.
The stator passed the flow chart in the garage area.

Still a no go, the bike will not run under it's own power (something it did last season)

Replaced the reg with the electrex unit.
Swapped the stator with another off my parts bike.
The Reg passed the flow chart test in the "garage" area.
The stator passed the flow chart in the garage area.


Still no go. When tested directly, the output of the RR isn't sufficient to light a 12v test light let along run the bike.

The REALLY interesting thing is that as the bike dies and is spinning really slowly, there is a spike in output or the RR from about 1.8v to 3 or 4...

The rotor on the bike look fine, and I can't discern a differance in pull between it and the other parts bike(just casually using a screwdriver).

What else can I check.. please help!


Thanks,

Jim

 

[graham harron]

are you SURE the battery is good ??

 

[Redman]

Sounds like you have a real puzzle there. So basically its like every part checks okay, but the entire system doesnt function. Well, either the parts are not connected correctly, or one of the parts really isnt okay.

You say "stator passed flow chart". You measured stator voltage(s) at mid rpms with stator disconnected? You ohm checked the stator?

When you say "output from RR of 3 volts", what-where-how you measuring that? This with everything connected, and measuring voltage acrost the battery?

Is battery fully charged before starting these test?

 

[bradleymaynar]

are you SURE the battery is good ??

I'd have to ask the same question. Have you tried a new battery? It's something the bike is going to need, so why not try that route first (granted that your question isn't answered here first).

Brad tt

 

[earlfor]

Re: Charging Challenge - WOW

Your bike does not run off the stator or the R/R. You can remove both of them and put them on your workbench and the bike will start and run just fine and normal. The bike runs off the battery. If it will not, then your battery is toast, or you have a poor connection on one or both terminals.
Cehck the main ground from the battery neg to the top of the transmission case. Your problem is your battery and connections.

Earl

Still no go. When tested directly, the output of the RR isn't sufficient to light a 12v test light let along run the bike.

 

[Anonymous]

I cant imagine how it could happen but is it possible that your rotor has lost its magnetism?

 

[Anonymous]

You say "stator passed flow chart". You measured stator voltage(s) at mid rpms with stator disconnected? You ohm checked the stator?

When you say "output from RR of 3 volts", what-where-how you measuring that? This with everything connected, and measuring voltage acrost the battery?

Is battery fully charged before starting these test?

Stator voltages are correct(measured mid rpm, directly on the stator wires in AC mode)

The stator ohms out correctly, and isn't contiguous with ground (this goes for both stators I've tried.

the 3 volts I was referring too were the isolated RR output (which I loaded with a test light), not sure if it's a feasible test since I know the RR output is load related, but it seems to be consistent with what is happening when it is hooked up to the bike.

 

[Anonymous]

Re: Charging Challenge - WOW

Your bike does not run off the stator or the R/R. You can remove both of them and put them on your workbench and the bike will start and run just fine and normal. The bike runs off the battery.

Hi Earl,

True, however on the gs700ESF and many other bikes, you can conversely put the battery on the bench (once the bike is running) and the bike will run fine without it. This is something the bike used to be able to do, and cannot now... with or without my battery (which is holding a charge and the specific gravity checks ok)

 

[Anonymous]

I cant imagine how it could happen but is it possible that your rotor has lost its magnetism?

I'd considered that.. and the possibility is there. From what I understand the usual reason that people replace starters is if they are physically damaged, I haven't been able to locate a single instance of the rotor lossing it's magnetism. A friend of mine pointed out that it is possible to weaken the magnetic field of permanent magnets with other magentic fields, so if somehow by the original regulator dying (now no longer in the system and the cause could have been the massive resistance caused by the bad connections, which have since been direct wired and ohmed) it could have caused the stator to act as an electromagnet and cause the stator to weaken??? Dunno... the most curious thing is the spike in output RIGHT as the bike dies down (maybe under 100 rpm in that last split second before the crank stops turning)

 

[earlfor]

Re: Charging Challenge - WOW

OK then, lets go back to square 1. The charging system is step two.
It is a fact the bike will run fine with no charging system installed if the battery is charged and has normal capacity. If your bike will not start and run off a fully charged battery, your problem (or at least part of it) preceeds the charging system. With the charging system disconnected and your headlight fuse or bulb removed, turn the ignition on and check voltage to the coils. It should be close to the same as battery terminal voltage. Take a voltage reading also while simultaneously pressing the starter button. With the ignition on, check voltage at the ignitor box.

If any voltages are abnormal, remove all fuses except ignition to locate the circuit that is causing the abnormality.

Let me know what you find/do.

Let me know what the voltages are.

The bike must run normally if all voltages are correct. In a nutshell, if it does not, then they are not.

Earl

Hi Earl,

True, however on the gs700ESF and many other bikes, you can conversely put the battery on the bench (once the bike is running) and the bike will run fine without it. This is something the bike used to be able to do, and cannot now... with or without my battery (which is holding a charge and the specific gravity checks ok)

 

[Anonymous]

Re: Charging Challenge - WOW

OK then, lets go back to square 1. The charging system is step two.
It is a fact the bike will run fine with no charging system installed if the battery is charged and has normal capacity. If your bike will not start and run off a fully charged battery, your problem (or at least part of it) preceeds the charging system.

Hi Earl,

The bike runs fine off of the battery with the charging system disconnected. Sorry I didn't make that clear earlier.

 

[Anonymous]

Well.. I at this point I think I'm going to just buy a new stator from electrex. It seems everyone is as stumped as I am.

Could it be that the stator "checks" out against the test methods outlined in the stator papers but is in actuality bad? Can anyone think of any other tests? I was contemplating pulling the rotor off of the parts bike, and spinning it with any electric motor and try the two stators I have against a rotor that hasn't been tested yet. I'll post the findings.

 

[dpep]

Re: Charging Challenge - WOW

Rewired and checked the stator output wires directly to the regulator.
Rewired and checked the ground direct to the battery.
Rewired and checked the power out directly to the battery.
The Reg passed the flow chart test in the "garage" area.
The stator passed the flow chart in the garage area.

Try moving all of your wiring back to stock configuration and see what happens. I had a problem after replacing my my charging components a couple of months ago and that seemed to fix it. I had only made one minor change and it was one that several other members have done. But it runs fine now, so I am not going wonder about it.

The rotor on the bike look fine, and I can't discern a differance in pull between it and the other parts bike(just casually using a screwdriver).

What else can I check.. please help!

Are you saying that the stator cover just comes right off after you take out the screws? You don't have to overcome a magnetic pull?

 

[Anonymous]

well I broke down and bought a new stator from electrex in hopes that the flow charts in the garage section were somehow missing something, or I had tested something incorrectly. Installed it and VOILA... NOTHING. So the ONLY thing left in the charging circuit is the rotor... never heard of one going bad over a winter sitting but oh well. I haven't the cash to purchase a rotor at the moment since I blew the whole wad on a regulator and a stator.. but perhaps we might think about adding rotor to the flowchart, as although it is rare they go bad, they obviously do.

 

[IanFrancisco]

I'd also check the new Electrex stator and RR to make sure they aren't bad by some fluke. I've heard several people badmouthing Electrex lately, one had a RR fail after only two months and another had a stator toast its insulation after a short time, most likely due to not getting the wiring and connectors in pristine shape before buying the expensive parts. Something had to make the original parts fail...

I bought a used stator, rotor and left engine cover for my 1980 GS450 on eBay for $50. The stator seem to be the same as for larger bikes incl. GS1000's. If the rotor would fit your bike I might let it go cheap...

 

[Anonymous]

the stator and RR both pass the same checks as the originals did, so are good according to the flowcharts in the garage area. I am definately in the market for a rotor(and puller) as it is really getting nice these days and I'm missing out!

 

[IanFrancisco]

Here's some part numbers I found for an '85 GS700ESF.

From PartsFish at powersportspro.com,
ROTOR 31402-08A00 $167 and discontinued

from BikeBandit.com,
ROTOR 491123-001 $212 and still available.

For that kind of money I would look into getting my rotor re-magnetized. How hard could it be?

The part number for the rotor I have is supposedly 31402-45030 ('80 GS450ST). Haven't checked the actual part yet though...

 

[Anonymous]

Yeah those are the same numbers I saw.. in the bike bandit pics the rotor you have is different(no threads for the puller on the upper part of the center hub, just flats so I guess it screws off or something). The rotor new is big money... I'm going to keep watching for used ones and hope I can find one I guess.

Thanks

-Jim

 

[IanFrancisco]

I hope you're right about the rotor. I don't think I've ever heard of a rotor going bad by losing its magnetism. I have heard of the magnets falling off a Kawi EX500 rotor. Some of the old 60's bikes had an "exciter" coil on the rotor, connected thru brushes and an armature to the battery, basically a rotor that was an electromagnet. If the battery was weak or went dead, no power for starting even with a kick-start. If you're getting close to 50 or 60 Volts AC out of the stator at 4500 or 5000rpm there's no way the rotor's that bad. Guys with the EX500's with broken magnets just break off the magnet on the opposite side and ride like that. It would be handy if you could beg borrow or steal another rotor to try, just for troubleshooting purposes. Obviously if you had the same trouble with a different rotor you'd know to look elsewhere. I think I would get a 1 or 2 Amp battery charger and just ride anyway. $29.95 at Sears. Disconnect the lights if they can't be turned off. You could probably ride for 8 hrs. before the battery got too weak. Even with the lights on I was able to ride an hour and a half before the battery got too weak to run the starter, and I was still able to push start it (easy when the bike only weighs 400lbs.). Only once did the battery get so low that I forgot and flipped on the signals just as the light turned green, which caused an embarassing stall requiring me to push to bike out of the road with cars waiting to go, then do a bump start at the side of the road. That got my heart rate up a bit!

 

[Anonymous]

Hey Ian... that's a great work around until I can solve the problem.. I pulled the old airbox in favor of cone filters, so I have a huge area under the seat... so I could put a car size battery in there almost. I want to participate in the Ride for Molly Bish coming up June 26th, and this might be the cheapest way to do it. I think I'll also see what kind of current the bike draws while running and then get a decent idea of the ride time before I die ha... ah well. I wish I had the later style all-in-one case alternator like the katanas.