Flat battery bike died

It is tempting to push the tips of the probes onto the copper rings. However, the copper is soft and the probe tips will leave indents. See how Weekendrider is avoiding this issue by placing the probes on their sides not the tips.
 
Put a voltmeter on it at home and its not charging.
Why do forums seem to jump to worst possible conclusions.
e.

well to be fair we only have the benefit of your brief observation and no testing data to go on.

Any reasonably charged battery should give you at least 50+ miles maybe double that after all its only providing an ignition spark. In a suspected non charging situation no other electrical loads should be used at all including signals and lighting which have a heavy load.

As Griz and Scott said ,....from your description it sounds like you could also have a short situation as well . It might be prudent to attach your Ampmeter in series with the battery and check for any excess loading with the engine running and everything else turned off.

When testing your rotor don't forget to check the resistance of your meter and leads first by putting the probes together . if there is any reading you will need to deduct it from your Rotor resistance reading.
You might find this video informative.
 
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You could have it rewound or get a different rotor (ebay?). Maybe gggGary has one, or someone else. Put an ad in the classifieds here because it's really active. Another alternative is see if a local auto electric shop can rewind it. I've always wondered about that. Good ones can rewind car alternators. Don't know if they pot them with glue like these rotors. Note if you have TCI ignition the rotor must be a TCI rotor.

http://www.xs650.com/threads/custom-rewind.13364/#post-135020
 
.8-.9 ring to ring and .5 touching wires together = big fail
What now?

Like XJWMX says your best bet is to get a good one off ebay if you can but prices of X650) stuff is still rocketing in price here in the UK anyway. Cheapest I can see is £40 or 68AUD

I expect a rewind would be expensive but you would at least have a perfect Rotor with a warranty
There is the option of fitting a complete aftermarket PMA (permanent magnet alternator) system but that will be hugely expensive. The only advantage I am aware of is that it will charge at low revs but frankly how much time do we spend at low revs lol. Most of us that like to keep our bikes original would choose one of the first 2x options as the original charging system is perfectly adequate when working correctly.

I believe your bike is a 79 Special like mine in which case it should be a non TCI ignition with standard pre 80 rotor
 
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You can't swap the brushes around on your model. The mounting brackets are different .....

9nokSV2.jpg


Swapping the brushes around is only possible on the '80 and newer models. Both their brushes are the same. In fact, they are the same as the earlier outer brush .....

Ox4cW8Y.jpg


Although no longer available from Yamaha, original new ones are readily available on eBay. There are also lots of aftermarket replacements but if you shop around, you can usually find originals for about the same price. It's odd to see your inner brush worn more than your outer. My best guess is someone replaced the outer already.

There's a slim chance your charging issue is due to really dirty slip rings not making good contact with the brushes. You might try cleaning them and then re-testing the rotor. It's cheap and easy, just use a little chrome cleaner on a rag. Here's mine with the outer ring cleaned, inner not done yet .....

GHoeRsM.jpg
 
Well, they were less than an ohm on a meter. That's too good contact already :D

yep .... I reckon thats pretty conclusive too :) that Rotor is fubar

Its easy enough to de-solder ,swop and re-solder the original brackets onto any other brushes that physically fit the holders . You can file the brushes easily enough to modify their dimensions .
 
X, I shared a tale of grief and humiliation with you for a couple of reasons, and one is to advise you against trusting used rotors, they're just waiting to strand you. The value of a rebuildable rotor core (dead 'un that can be rewound) is about $50 US, and that's the value I put on any XS6560 rotor that hasn't been rewound. Again, the problem isn't that rotor design or manufacture was poor, it's that offgassing, heat, and vibration have put 40-odd years of stress on them. There's an XS650 Club in Australia, and its members include some of the most tech-savvy guys you'll ever meet. They'll know where to get your rotor rewound. Google for contact information.
 
Nothing whatsoever wrong with using used parts !. Lets face it, the whole bike is 40+ years old
. If the age and reliability of the parts were a significant concern we would never go out on the damn thing:rolleyes:

Any Rotor can fail at any time it doesn't matter whether its 40 years old or brand new .
Its the same with the whole of the charging system and components.

There is little point in my opinion in shelling out for an expensive brand new rotor or rotor rewind for reliability sake and then leave the 40 year old Stator , regulator Rectifier, Wiring loom, Fuse block etc all in place .
 
These rotors, like the rest of the engine, go through heat cycles. Every cycle "stresses" the insulation and resin that insulates and holds the winding's in place. Eventually, they fail. A 40 yr. old rotor is nearing the end of it's life. A used one can work perfectly fine, but odds are... it's pretty close to the end of it's life. Put a new (or rewound) one in and the clock resets.
The rotor in my SG is shot. When I get to that point, I'm going to buy a new or rewound one. Not gonna chance one at the end of it's life and always wonder how much time it has left. Asked for or not, there's my opinion:)
 
Here's a new one on Amazon. 1 yr. warranty.
67 bucks and free shipping. I can't vouch for it, but at that price it might be worth a go....
 
I think someone here got one of those recently and it has no timing mark. That's a rather major omission in my eyes.
 
. A 40 yr. old rotor is nearing the end of it's life. :)

probbly but then it depends to some extent on how much use it has had and how well it has been looked after . The rotor on my 79 had only done 12,000 miles still works fine
If I was going to put a brand new Rotor on my bike at nearly $200 then I'd also budget for a new regulator rectifier fuse box and stator as well otherwise I think it would be pointless
 
Its very hard to find a good source for rewinding rotors at a sensible price. When i rung around the country i was getting quotes from well over the $200 to $400. I belong to the Aussie 650 club and talking to a committee member he told me of a guy he knows, (didn't divulge who), who would do back yard rewinds for around $120 each with a proviso he would only do a min of 3 at a time.

Problem with finding these guys through the club these days is that the president of the club is also the owner of Geofs XS, so there is a push towards his business rather than finding an alternative cheaper or more reliable source for the penny conscious members.

Mikes XS Rotors have been found to have poor tapers causing the rotors to wobble.

A better option may be to buy or get given a dud from the US and get it sent to custom rewind then sent over here. It will still be close to the $200 Aus mark but they do have a good reputation. Take note they use heavier winding's so when testing the readings may be in the 4 Ohm mark
 
For what it's worth, I've had a good dozen complete XS650 alternators from parts bikes in the stash over the years. Over half of the rotors were bad. Only one stator didn't meet spec when metered. I've seen numerous XS650 rotor failures on group rides and have had two go bad on me on the road. Never seen an XS650 stop charging due to stator failure.
 
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