Stator Output 3vac,5.5vc,5vac running

[twistedwankel]

Okay I know the Stator is not putting out any significant voltage. This battery is only 4 months old and fully charged at 13vdc. This has been a gradual thing over the last 2 months. Battery weak after an hour ride in 90F heat and had to push start at gas station.

81 GS750E, 20k miles. All stock mostly original. Runs and rides perfectly.

I followed the Stator and RR testing procedure and did it twice over two days. I also went to Auto Zone and they verified my charging system at 12.2VDC and 0.7amps right off the battery after I fully charged it and rode there with the lights off.

I'm just one of those people that doesn't like to replace things that make no sense. The Stator and the RR both pass every test with flying colours except for the actual running no load disconnected stator wires AC. The voltages are 3, 5.5 and 4.96vac.

I will order my new stator after I get my new impact driver from ACE hardware and get the cover off? Guess I just have to see this thing to visualize what fried? Also to get measurements to verify I will be getting the right one to put back in.

Is there any reason to replace the RR too? It passes all tests and all the wires are cleaned and have perfect continuity in the whole charging system. I wish I knew why this failed so it won't happen again. I believe this is the original Stator but I am the 3rd owner so who knows for sure?

To me it's just a puzzle. All three legs ultra low volts. Only thing that makes sense is that one is lower than the other two.

[twistedwankel]

Mission Completed answered own questions.

1. If the voltage is not 45vac at idle (on all three legs of this 3 phase alternator) or 75vac at 5k rpm the Stator is dead. As soon as I plugged the leads into the rectifier and checked it read 13.4 vdc at idle. Perfect.

2. Irrelevant of all the other tests if it doesn't put out the right voltage on all three legs while disconnected it's junk.

3. The diode tests and voltage DC across the relay for the rectifier validation are absolutely correct.

A. The most important tool to do this is the reversible Impact Driver Kit with two different size phillips heads I got from Ace Hardware via order.

B. I wish I would have had a gasket on hand before I started this. I got a used Stator off ebay as I still wasn't convinced the research was right. I installed it and left the imbelical loose so I could test the output right off. It was right on 45vac at 2k rpm and 90vac at 5k rpm. End of problem. God bless honest ebayer/bikers. Anyway it bench tested better than my old one so I felt reasonably confident.

C. I ordered a new gasket as the oil drip won't allow much riding and I refuse to use the Blue crap. Then I realized I could cut my own gasket from 1/64" stock from hardware store. 9" x 36" for $1.79 - a factory gasket is $6 plus shipping and the wait.

D. I replaced a couple of the long screws in the sprocket cover with 100mm x 6-1.0 studs and used acorn nuts with a couple washers to make the length right without cutting - and to get a socket on in. It is near impossible to find the bastard lengths 95mm and such of screws for these old bikes. A couple of those phillips were shot from corrosion and beating on to break loose. The original ones on the stator housing are still perfect so I reused them all and used never sieze on them.

E. I took pix of the process and if I ever figure out how to load them up to the site I will. It's pretty straight forward once you do it twice.

Finally. I took the bike for the all critical 2 hour road test. Shut it off and restarted it several times while still rolling Got home put it on the trickle charger and within 3 mintues it showed full charge. SUCCESS.

Bolt sizes/lengths for stator and sprocket covers:

Stator Cover (10 screws total)
All 6mm-1.00, following lengths 1=30mm, 7=35mm, 1=40mm, 1=45mm
*If you forget where they go put them in the holes and the penetration on the bottom hanging out should all be the same length for all of them.

Sprocket Cover (6 screws total)
All 6mm-1.00, following lengths 1=30mm, 1=55mm, 1=70mm, 1=85mm, 2=95mm

[twistedwankel]

Photo gallery

http://www.kodakgallery.com/Slideshow.jsp?mode=fromshare&Uc=8q0ry7g.7t0rlckc&Uy=-arjypt&Ux=0

[Eli69]

Thanks for bringing this up, it's one of the things i've been putting off dealing with for a while. my stator is putting out somewhere in the area of 30 - 35 vac in each leg. i thought that maybe the magnets in the rotor were losing strength. it would seem though that somehow the coils that the make up the stator must be breaking down in some way.

I'll probably deal with this over the winter but for now i must ride whenever the weather allows. i use a battery charger and a lot of semi-dangerous riding without lights now to keep things going.

A question - could you tell me the resistance across your old stators leads? I wonder if that is different from the resistance on the working part?

[bonanzadave]

Nice job Wank !

Im gonna tackle this myself. All my indications are the same as yours. Where did you put the meter probes when checking the stator ? Did you happen to see another stator when looking for yours ? The Electro Sport stator is $120.00. What did you pay off Ebay?

Thanks for some really great pictures. Explains alot.

[twistedwankel]

Ohms

Thanks for bringing this up, it's one of the things i've been putting off dealing with for a while. my stator is putting out somewhere in the area of 30 - 35 vac in each leg. i thought that maybe the magnets in the rotor were losing strength. it would seem though that somehow the coils that the make up the stator must be breaking down in some way.

I'll probably deal with this over the winter but for now i must ride whenever the weather allows. i use a battery charger and a lot of semi-dangerous riding without lights now to keep things going.

A question - could you tell me the resistance across your old stators leads? I wonder if that is different from the resistance on the working part?

When the original was on the bike I got 0.5-0.6ohms across every combination. No indication of a problem there.

When the Stator was off the bike I got these numbers:

Old Y-BlW 200 ohm, Y-GW 6 ohm, BlW-GW 100 ohm

New/used off bike all same combinations 0.6 ohms each pairing.

That was the only set of different readings from allowable other than the output voltages of course.

I'm sure the insulation value has broken down over years of heat. I'm going to look for a local motor rewinder to fix my old one for a replacement. Should be cheaper and better than a new one with new windings. I don't think I have the patience/ability the others do to follow the do it yourself instructions on this site.

[twistedwankel]

Nice job Wank !

Im gonna tackle this myself. All my indications are the same as yours. Where did you put the meter probes when checking the stator ? Did you happen to see another stator when looking for yours ? The Electro Sport stator is $120.00. What did you pay off Ebay?

Thanks for some really great pictures. Explains alot.

Under the airbox is a rubber bag of wires from the Stator to the Rectifier. Pull those apart and insert the meter probes into each pair one at a time 3 times (NO GROUND) as this is a 3 phase AC ungrounded generator.

You can clip one and test two bing bing at idle. Just make sure they don't go to earth while you're doing this. I stuck one probe in the back tight area of the insulator so it wouldn't touch anything while I raced the engine.

I got lucky and found one missing wire ends, a broken insulator and went on blind faith for $25 - but I only wanted it for the short term. Now I can easily change the thing out it's not a big deal anymore. I'll get my old one rewound now that time is on my side.

There was one more brand new old stock Suzuki for $150 buy now - so you can do better than that from the listed suppliers with a warrantee I think?

Best of luck getting your old one out.

BTW there is a second set of more involved pix showing the wiring and connectors for the Stator/Rectifier on the same slide show you went to. Look at the bottom of the sheet for view gallery 2.

[flyingace]

It isn't necessary to produce 75 V AC. It depends of the specs of the stator. I have one from Electrosport that only puts out about 50 V AC, but the specs on their web site indicate that's what the output should be. I'm not sure I would replace a stator putting out 35 V AC unless it fails to charge the battery.

[Eli69]

this is very interesting because i've read on this forum that the gs charging system is the weak part of an otherwise extremely well built bike. that's why i wasn't surprised when my battery started going dead all the time. (my typical luck) i'm starting to wonder if my stator is not the problem though because, while riding tonight i noticed the lights dimming and occasionally brightening up real nice. there was no pattern to it, didn't happen when i hit a bump or anything that might suggest loose connections. i wonder if that was the way yours went?

i still haven't ruled out a regulator problem. the regulator and rectifier are seperate units on the 78 model.

glad you got your scoot straightened out twisted, that bright headlight is definitely a necessity.

[txironhead]

If you ever want to do those housing screws the right way, check this out:

http://motors.search.ebay.com/_W0QQsassZthunderboltzca

I'm gonna order a set for my bike soon hopefully, when the money situation stabilizes. Stator housing, sprocket housing, points cover, clutch cover, starter cover etc. in stainless steel Allen head bolts for $20 Buy It Now price, plus $5 shipping, 100% positive feedback. And yes, he does have bolt kits for 81 GS750E, already asked, he just doesn't have an auction up for them yet.


It's not what you ride, it's.......get that $%@# harley outta my way!O

[twistedwankel]

Thanks

If you ever want to do those housing screws the right way, check this out:

http://motors.search.ebay.com/_W0QQsassZthunderboltzca

I'm gonna order a set for my bike soon hopefully, when the money situation stabilizes. Stator housing, sprocket housing, points cover, clutch cover, starter cover etc. in stainless steel Allen head bolts for $20 Buy It Now price, plus $5 shipping, 100% positive feedback. And yes, he does have bolt kits for 81 GS750E, already asked, he just doesn't have an auction up for them yet.


It's not what you ride, it's.......get that $%@# harley outta my way!O

This is exactly what I had in mind when I went to the bolt store. Thanks a ton. I emailed him too. Hopefully he'll fix me up for what is a quite reasonable price delivered from Canada.

[twistedwankel]

Don't do alot of night riding

this is very interesting because i've read on this forum that the gs charging system is the weak part of an otherwise extremely well built bike. that's why i wasn't surprised when my battery started going dead all the time. (my typical luck) i'm starting to wonder if my stator is not the problem though because, while riding tonight i noticed the lights dimming and occasionally brightening up real nice. there was no pattern to it, didn't happen when i hit a bump or anything that might suggest loose connections. i wonder if that was the way yours went?

i still haven't ruled out a regulator problem. the regulator and rectifier are seperate units on the 78 model.

glad you got your scoot straightened out twisted, that bright headlight is definitely a necessity.

I rarely do the bug biter night riding so the headlight thing never came to my attention until it was dim on the back of a car ahead of me at a stop light. I did replace the battery (probably unnecessarily) about 4 months ago as I thought it had a bad cell. I did notice that when very hot after riding over an hour that the starter would drag if I didn't let the engine cool down for at least 3-5 minutes before trying to restart it at the gas station. I think the most important voltage check which is the easiest is to go across the starter relay + to a good ground and look for over 13 VDC. I am seriously thinking about putting a permanent all weather volt meter on the bike for future peace of mind on back roads. Even my 84 Ford as one. Just have to figure out an acceptible location that it doesn't look stupid. Even an idiot light would be better than nothing.

[twistedwankel]

Fantastic Tip on SS Hex allen engine bolt set

[quote=txironhead;525676]If you ever want to do those housing screws the right way, check this out:

http://motors.search.ebay.com/_W0QQsassZthunderboltzca

]

Fantastic tip.

These take all the worry about stripping the phillips screws away forever.
Doug

[bwringer]

http://www.casporttouring.com/store/merchant.mvc?Screen=PROD&Product_Code=14124&Category_Code=Electronics

Nifty little backlit voltmeter/thermometer/clock thingy for $21.48. I don't know how well made it is, but it's one of those things I might try one of these days just for giggles.

[twistedwankel]

5 Function Volt Meter for cheap

Digital 5-Function Volt Meter

You've got to love this site.

One of the other members posted this info in another thread.

It took me two tries to get one that works perfectly but what a great device So I had to eat the return postage...so what...it's still way cheaper than a normal voltmeter or idiot light setup.

I love this thing. No more VOM as it's constantly attached to the battery and tells me what's up PLUS 4 more features

Normally I hate Chinese products but this time they hit a homerun and no one else can touch it.