Stator failure

[sdhow]

Ok...finally got time to look at 386.

A few weeks ago, got stranded with a completely dead battery a long way from
home. No little red light or nothing until it just died. Caught by suprise, as
I had just replaced the battery because it was starting hard...figured the six
y.o. battery was wore out. Had the new battery checked out; seemed ok, had it
quick charged, threw it back in and rode it home...light came on 10 miles from
home.

Threw the battery on the trickle charger and light was now off again. Just got
back to it today.

Stator is putting out 65+ VAC at the connector, but system is only showing
12.8-13.0 VDC at the battery. Did a current leakage test, not showing a short in
the system, but thought I'd throw a new V-reg on and see what the output to the
battery looks like again. Still at 12.8-13.0 VDC, but I notice the new V-reg is
getting really hot. Went back and checked the continuity of the stator
and...voila! I've got continuity between each of the three stator spades and the
ground.

Ok, so all the troubleshooting guides say "stator fubar...replace stator".
Fine...but I'm wondering what causes this (heat, overloading of the stator)?
This is the second stator in this bike (1st at 13K, now again at 27K) and I'm
wondering if these factory stators are inheirently weak or what. I do have all
of the factory accessories on my bikes and higher watt driving lights (30W each)
and headlight, but that's it.

[mharrold]

I have 18k on #459 and it has the original stator. I do not have any electrical accessories, except an oil cooler fan, and original wattage bulbs.

[wytfut]

I'm not electrical engineer at all... but have listened since I purchased my X back in 2001.

According to the guys that know.... our stator is of poor design... and about annually the topic comes back up with some research, and lots of discussion.

I replaced my first stator due to burn out 2 years ago. At around 19k miles. First one went out, due to me not paying attention when I put the primary case back on, about 6k miles.

From what I understand to keep any life in our stators....: Keep our engines cool (you don't have an up dated tune and a fan assisted oil cooler)..... get it done as soon as possible. Don't overload them.... I worked on a Jenny a few years ago, that was a show bike.... This owner had every aftermarket electrical toy out there on it.... and it burned up the stator, which I replaced.  Keep a close eye on all the connectors on the charging system. Many references to the stator/regulator connector... check it out... and the others......

Sooner or later, the spare stators are gonna run out, and I'm hoping one of us owners, or the vendors find a good place to rebuild or they find us a good "other" brand replacement.....

I don't know if any of the present vendors are rewinding stators, but one of the past vendors had someone doing it, and the life was extrememly short....

[sdhow]

Thanks for the input, Bruce!

We're talking about it over on the Yahoo (EHRB) site,too, but was hoping one of the Road Crew folks might weigh it on the topic.  I did replace the stator today AND the rotor; factory rotor had FIVE drill spots on the outside of it...an attempt to "balance" a bad rotor by the factory? Noticed funny wear on the inside of the rotor...you guessed it, opposite the drill spots! Made sure I oriented the oil passage on the crank 180 degrees to the orfice on the rotor.

Still getting low voltage to the battery at 3K rpm, but 14-14.4V @ idle.  Could it be a faulty voltage regulator?

Sean

[sdhow]

Update...traded out a known "good" V-reg off of 580. Better output, but results
are a little perplexing.

Voltage readings at the battery:

14.3 VDC @ idle, w/o driving lights
13.3 VDC @ idle, w/driving lights

13.75 VDC @ 3,000 rpm w/o driving lights
13.82 VDC @ 3,000 rpm w/driving lights

Shouldn't the output go UP with increased rpms? Why the full volt drop at idle
when the driving lights are flipped on, but a slight increase in volts at 3k
rpm?

Any ideas or comments?

Note: I've swapped out the driving light bulbs for halogens (H-7600), which are
37.5W each, compared to the factory 4449s, which are 30W each. This is adding an
additional 15W to the system. Can't imagine this is a huge difference, but
thought I'd mention it.

[wytfut]

Yeah... I've been following along on the resource board.
Grizz is really experienced.... plus that other dude (I can't remember his handle on the site) is too.

So me stating that the more you add to the stators load.... is really not true, according to what I'm reading. And I was quoting from past posts from over the years.

it sounds like now, its mostly just make sure you keep it cool.....

[dynamike35]

I always learned that volts x amps = watts , so 12v into 15w = 1.25 amps. Not a whole lot but still adding to load. I don't know what the EH charging system is rated for(in watts) but you can check total load with an ampmeter between bat+ and +cable(disconnected) and read total draw with ignition on and EVERYTHING on,horn,brakelite,lites,flashers,dr. lites,fans,etc.Two things to remember is low beams use more than high beams in alot of cases and some things draw alittle more on startup(surge) so make allowances. I also agree that heat is an enemy to windings(heating/cooling)breaks dowm the insulation.