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Discussion Starter · #1 ·
I am wondering that if my rotor is contacting the stator (There is a scrape mark on inside of the rotor), would it not put out AC voltage. One time I pulled the rotor off using the wrong tool, and I may have bent it in that spot where it looks like it rubs as it spins around the stator. Since I have replaced the usual parts and they didn't fix it, I'm wondering between the rotor rubbing and bad replacement parts. My battery charges to over 13volts with my trickle charger. I have replaced any burned wiring, bad connections and replaced with better stuff. Any attempts to help figure this out are greatly appreciated! All who answer people's questions are super!
-Jeffy.
 

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Hello Jeffy,

Seems you have a Honda. . .good bikes, had a few back in the day. Scrape mark inside the rotor. . .Does the rotor spin over the
stator ( the ring with coils wound on it) ? or does rotor spin inside rotor where coils are facing rotor? Does it look like part of the
coils have been chewed up? if not. I would not worry about that scrape. could be it has nothing to do with anything.

Now, how many wires coming off the stator? 2 wires means it is a single phase winding. 3 wires and it is a 3 phase winding,
same as a car alternator. If you have a multi-meter, you can set it to ohms and check for a shorted winding or a winding that
is touching ground, if it is chances are it will show signs of having been overheated. You connect one lead from tester to a good
ground, and touch other meter lead to leads from stator, one lead at a time. if you get continuity to ground, stator is bad.

If this test shows no grounds, then what you do is, with engine running, set meter for A.C. volts say 50. and see what kind of
voltage you get at idle, 2,000 and 3,000 rpm and compare these voltages at those engine speeds to what the service manual
says. Also there could be a battery charging fuse, if it is open, battery will not charge. most likely bike has the square fuses in
different colors and have flat metal tabs. if the fuse is clear and you can see a break in the link. it opened on overload, BUT if
the fuse is blackened, it is most likely a short circuit.

If you get some voltage but not what the book says and the rotor has permanent magnets, might need a new rotor.
or it might be a wound rotor with slip rings that come in contact with brushes. A new regulator won't do skwat if the
brushes are shot or the rotor's winding is grounded or open. in this type of rotor there is a winding in the middle and
you have interlocking fingers like fingers on 1 hand between fingers of other hand.

So Jeffy check the stator to see if there are any shorts to ground, if not check for voltage.
 

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Discussion Starter · #3 ·
Yeah, the rotor rotates around the outside of the stator on these Japanese sportbikes. I just needed to cover the possibility of the rotor scraping over the stator causing a fault, before I do anything else... My first stator was burned and the connector from the reg/rectifier was melted and wires burned. The connectors are made of ordinary plastic, so it's common that they melt and cause more problems! I hard-wired mine to prevent a repeat, but I have another problem. So, I do all the tests over again, but if the rotor rubbing is an issue, then maks nix!
 

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I think I would try and get another rotor, chances are this one was off and got dropped pushing in the inside of the rotor,
causing it to possibly scrape the bobbins on which the coils are wound on. There are various kinds of course but a bobbin
would be a plastic like sleeve over a laminated core, most likely square-ish like. some coils might be visible, others might
have been taped. take a good look at the ends of the coils, you will see the laminated core and whether or not the rotor
was brushing it as it spun over the coils.

Any chance you have an electronic camera that u can take pics of the rotor and stator? anything look burned? Discolored?
 

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My first thought would also be (as ray suggested) the fuse between the charging system and the battery.
 

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Discussion Starter · #6 ·
This bike doesn't have a fuse for the charging system-I'll check again and make sure, though. That would be a nice, easy thing to fix! I do have a camera, but this is easy to describe: A scrape on the inside of the rotor, and scrape marks on the ends of the bobbins, which have steel or iron ends closest to the inside of the rotor, which rotates around these wire-wrapped posts(the stator). The rotor has permanent magnets around it. So, it looks like this one place on the inside of the rotor is scraping over the posts, or bobbins of the stator. I just don't know if that can cause the not-charging problem, though. Thanks, y'all, it's helping me think.
 

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Jeffy,

Do the coils look like they got heated up or do they have tape around them? It is possible that maybe vibration caused coil to
ground to stator core. We can stand around guessing what might have happened OR we can do as I said before, check for a
grounded stator. If you don't have a multi-meter you can grab a lite socket for a tail lite bulb and make a continuity tester.
you can even use bike battery where it is if negative is grounded. Take a long wire from battery+ to say a tail lite socket you
get at auto parts store or if you know how to solder, either way hook lite up and other end of lite goes to leads from stator.
if there is a ground in one of the windings or coils, the stator is BAD.

And you thought biking was all about riding? Jeffy biking is about a LOT of things ! and that is getting to know about all the
parts of the bike, not all in one day but over time, that is me anyways. I might need to have someone fix something BUT I
want to know why it had to be fixed and what was happening and what is supposed to happen.
 

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Discussion Starter · #9 ·
The stator passes static tests, as did the first one, though the first one had some blue (overheated) windings. I don't get nearly enough AC voltage: mine delivers 23VAC, all 3 phases @ 5000rpm and the requirement is 65VAC on all 3 phases @ 5000rpm. So, I'm going to replace the rotor. I'll post here if that's the cure.
 

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WOW ! that is a BIG loss of A.C. Volts. Sometimes permanent magnets do lose their strength. I suspect a new rotor will solve the
problem and your A.C. volts will return, as will a good battery charging voltage.
 
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