Question about rotor and charging.

[Eric12171]

Hi, this is going to be long winded,
I apologize.
I thought I had this figured out once , but nope.

The main question is is it possible that a rotor is bad without reading bad.
Where else could it short ?

The bike 79 xs650 special 13,000 miles
Bought as a non running bike
Stock parts
Seperate regulator and rectifier.

The harness was pretty butchered when I got it,
Now I’m thinking they may have been chasing the same problem?

New battery
New wiring harness -mikes (some wire colors don’t match) I was told by their support “they sub whatever colors they happen to have “. “ but it should work”

New stator and brushes . also mikes
New and clean ground wire from negative terminal to frame.bare metal

Will be updating reg &rec to what’s listed in the diy part of the forum when the parts get here.

Tested
Rectifier good
Regulator good
Stator good .8ohm on white wires
Technically.5-.6 my meter shows .2-.3 with the leads touching.

Old stator tests fine too

Rotor reads 5.6 at the slips so 5.3 actual

The bike runs this the battery drops,
Then have to charge it to get going again.doesn’t seem to run right either.

Through poking around at everything I found with the key on I was only getting 1.2volts going to the postitive brush on the stator
When i unplug the connector it reads full battery voltage at the positive lead

Plug it back in , remove the connector from the positive brush itself the lead is full power .
Reconnect 1.2v
Remove the negative brush
I get full power to the positive
Bush brushes in remove the stator and it has full power, with ignition on.

I thought one of the wires was making contact somewhere in the middle or figuring all of that out.

So I reinstalled my old stator.
Got full power to the brush
Started it .
It sounded great. Charged the way it should .
Shut it down , grabbed a beer to celebrate.
Started thinking about what to do next.

Tried it again and was only getting 1.2 volts again.

When installing the stator it definitely takes some effort to get it in place.

Do rotors swell for any reason?

I’m stumped as to what’s going on
This is the first one of this model I’ve gotten this involved with.

I’ve read a lot of things on here but nothing seems to be quite the same problem.


If anyone has a suggestion. I’m all ears

I’d get a new rotor , but don’t want to do that til I get some different opinions as to what it might be. Don’t want to throw another $120 unnecessarily

Thanks again.
Eric

 

[jpdevol]

Weird. One thing that I would check, given symptoms, is to check the brush block mounting screws going too deep and touching the rotor - shorting brush

 

[Eric12171]

Thanks ,
I did check that as well , unfortunately it wasn’t it

 

[gggGary]

Run a jumper from the battery positive. a bad connection in a connector block or the ignition switch.
Double check all fuses, fuse holders also.

 

[Eric12171]

That works,
I’ll tear the ignition apart tonight and clean it up
Thank you. Hopefully that’s the problem.

Here are some pics.


The 1.1s are without the jumper
The 11s are with

 

[gggGary]

The iggy switch is often really bad inside, and usually can just be cleaned and reassembled.

 

[jetmechmarty]

So I reinstalled my old stator.
Got full power to the brush
Started it .
It sounded great. Charged the way it should .
Shut it down , grabbed a beer to celebrate.
Started thinking about what to do next.

It sounds to me like the MikesXS stator is junk out of the box. That wouldn't be a first.

The OE stator is a precision fit. There's a guide pin on it as well. The rotor does not swell. It's all a precision fit.

If your rotor is original to the bike, it is going to fail. The only question is when.

My rotor story:
I bought a new XS650 in 1983. In 2002, I decided to take a trip on it over 2,000 miles. I asked on the email board what spares to carry. They said rotor. I didn't. I started out south of Atlanta and somewhere in North Georgia I swapped my brushes as I suspected an issue. In Morgantown, WV my main fuse opened, leaving the bike dead. I replaced the fuse and drove on to Jamestown, NY. On the trip south I had another blown main fuse. Upon my arrival in Georgia I left the bike parked for a few weeks. The next time I rode it, I got three miles and the battery was dead. The rotor was dead shorted. I got a rewound rotor and it's been fine since.

 

[gggGary]

A simple U jumper in the switch conector in the headlight bucket should point right at the switch as the issue.

 

[Eric12171]

The iggy switch is often really bad inside, and usually can just be cleaned and reassembled.

The iggy switch is often really bad inside, and usually can just be cleaned and reassembled.

Hopefully it will be that easy.
I just fired it up with the jumper attached,
Sounds great ,
And for the first time my headlight even came on

Was going to add a video, but doesn’t seem to be an option on here ?

 

[Eric12171]

It sounds to me like the MikesXS stator is junk out of the box. That wouldn't be a first.

The OE stator is a precision fit. There's a guide pin on it as well. The rotor does not swell. It's all a precision fit.

If your rotor is original to the bike, it is going to fail. The only question is when.

My rotor story:
I bought a new XS650 in 1983. In 2002, I decided to take a trip on it over 2,000 miles. I asked on the email board what spares to carry. They said rotor. I didn't. I started out south of Atlanta and somewhere in North Georgia I swapped my brushes as I suspected an issue. In Morgantown, WV my main fuse opened, leaving the bike dead. I replaced the fuse and drove on to Jamestown, NY. On the trip south I had another blown main fuse. Upon my arrival in Georgia I left the bike parked for a few weeks. The next time I rode it, I got three miles and the battery was dead. The rotor was dead shorted. I got a rewound rotor and it's been fine since.

Thanks I think this is going to be a local only bike ,
So I’ll get some spare parts as I can for backups

 

[gggGary]

Was going to add a video,

 

[Eric12171]

A simple U jumper in the switch conector in the headlight bucket should point right at the switch as the issue.

Disassembled . Cleaned, sanded the contacts on the ignition.
It works.
12v in and out.
Get back to my positive wire 12v
Plug-in the brush 1.2again.


I tried the other hot lead , it goes to the neutral switch .
When that’s connected to the brush wire
That hits 10.8 .
It runs , but doesn’t charge.


Harness not wired correctly?

 

[gggGary]

I tried the other hot lead , it goes to the neutral switch .
When that’s connected to the brush wire
That hits 10.8 .
It runs , but doesn’t charge.

That doesn't sound right. the neutral switch wire (light blue) just provides a ground for the neutral light bulb on a 79.

 

[Eric12171]

Wiring harness and stator both from mikes
Asked them twice about proper fitment as well.

Top plug 3 whites in rear left green 12v black center gnd right blue 12v

Bottom plug 3whites rear
Gray supposedly to neutral switch
Red ground
Green to positive brush

 

[gggGary]

what color is the wire at the neutral switch?

 

[gggGary]

Is the neutral light working correctly?

 

[Eric12171]

Is the neutral light working correctly?

It is blue, at the engine
Their stator wiring it’s gray
Their harness wiring it’s green


No it stays on no matter what gear it’s in


I sent them those pictures and asked directly about that before I put it on .


Looks like I’ll be opening it up to trace wires

 

[gggGary]

Looks like I’ll be opening it up to trace wires

 

[Eric12171]

Exactly how I feel.
No way I can return it either

 

[gggGary]

Use a fuse but open the connector, ground the blue wire on the harness side, see if it's really the neutral bulb ground..
Then start testing on the stator side and find the wire that is connected to the neutral switch.
It'll take a little bit but you should be able to match up all the wires to where they SHOULD be the wires can be removed from the connector by pushing back a little tab from the back side to release the spade connector from the block.