Stator Removal / Replacement Write Up

[Matthieu]

So my 1 ohm looks suspiciously high compared to 0.18~0.28 [img]style_emoticons/<#EMO_DIR#>/sad.gif[/img]
Such a small resistance might be difficult to measure by a poor tester device. I will make the measurements with another tester device just to make sure.

<!--quoteo(post=212241:date=Tue 21st Jun 2011, 01:50 PM:name=celticbiker)-->QUOTE(celticbiker @ Tue 21st Jun 2011, 01:50 PM) <{POST_SNAPBACK}><!--quotec--><!--coloro:#0000FF--><!--/coloro-->I drained my oil before I started this job but there will always be about 0.5L in the bottom of the engine. In theory the tank should not drain because of the check valve but I didn't want to find out.<!--colorc-->
<!--/colorc--><!--QuoteEnd--><!--QuoteEEnd-->Hummm.. it is not a good news but thanks a lot for that information, I am happy to know what falls off a cover before removing it. I guess I had better drain the oil like you if I decide to go further and make the measurement right at the stator.

Cheers
Matthieu

[Matthieu]

I am about to remove the stator to have it rewound.. I re-read your tutorial and I have two questions.

<!--quoteo(post=157646:date=Sun 4th Apr 2010, 12:22 AM:name=celticbiker)-->QUOTE(celticbiker @ Sun 4th Apr 2010, 12:22 AM) <{POST_SNAPBACK}><!--quotec-->When you get it back, put the newly wound stator into the casing (don't forget to route the wires correctly) <!--coloro:#FF0000--><!--/coloro-->seal the grommets into place<!--colorc-->
<!--/colorc--> <!--coloro:#0000FF--><!--/coloro-->with instant gasket<!--colorc-->
<!--/colorc--> and leave in a warm place for 24 hours for the shellac to dry thoroughly (mine was still a bit tacky when I received it).<!--QuoteEnd--><!--QuoteEEnd-->
<!--coloro:#FF0000--><!--/coloro-->Grommets<!--colorc-->
<!--/colorc-->: I did not understand what the grommets are. Is it what I highlighted in red in the picture below? (I suppose the second grommet is in the inside, against the alternator casing?)
<!--coloro:#0000FF--><!--/coloro-->Instant gasket<!--colorc-->
<!--/colorc-->: I guess it needs to be of a special type for such a use. Can you recommend me a brand/type ?



Thanks
Matthieu

[Matthieu]

In the end I found a used stator (90euros). I put it in place with some medium strenght thread lock on the bolts.
I got rid of the old gasket's remainings using a cutter with care.
Now that everything is in place I measure 25V~ on the grey connector (with the 3 white wires coming from the alternator) at 1000rpm and a higher voltage at 4500rpm. At the battery terminals I get around 14,3V= so it is charging again and everything must be fine.
Thanks again for the tutorial and your messages!
Matthieu

[Aly86]

Hi, Thanks for the great advice on your post. I am about to tackle this as my battery dos not appear to be charging.

 

I have followed the steps as per the Haynes manual and the resistance between the 3 white wires is well in excess of what it should be for the 850.

 

The only point which is brought up in the manual is to check the problem is not in one of the white wires between the connector and the stator. i.e. a broken wire.

 

I have to say the wires look in pretty poor condition, so it could be the problem. Or is it the case that when you send the stator away to Robin he replaces the white wires as part of the work?

 

I have an multimeter for checking resistance etc, however not sure how the white wires are connected to the rear of the stator, it has 3 Phillips screws holding it in place, which look as though they are going to be a nightmare to get out, (currently got them soaking in WD40). If I do manage to get the stator out, will this give me access to take some readings and check the condition of the white wires?

 

Any advice is much appreciated.

[celticbiker]

The 900 has allen bolts holding the stator in place. I would think an impact driver would be your best bet for removal of Phillips head screws.

Once removed you could carry out a continuity check on the wires but I don't think they will be the problem.

Does he put new wires on?

Well to be honest, that's a good question. The first time I sent mine I cut the plug off (don't ask) and so asked him to put 500mm of new wire on for me, when I got it back I soldered it all back together.

When I got it back this time it was all neat and tidy with an insulating sleeve over the whole thing and it never occurred to me to check to see if the wires were new or not.

He's an amiable enough chap though, so a phone call couldn't do any harm.

[Studley Ramrod]

Aly, unlike the 900, a new stator for the 850 is much cheaper to buy. 

 

http://www.electrexworld.co.uk/cgi-bin/sh000001.pl?REFPAGE=http%3a%2f%2fwww%2eelectrexworld%2eco%2euk%2facatalog%2fOnline_Catalogue_Stator_Kits_424%2ehtml&WD=tdm&PN=G07%2ehtml%23aG7#aG7

[Aly86]

Fantasic, thanks very much to both studley ramrod and celticbiker for the advice. Given the price of a new stator with wires for the 850 is only £65, I will probably go for that, which will at least cover all bases.

 

Great stuff

[dmmsta]

Just to add to this superb post.

 

I've just spoken to Robin Williams (the re-wind man in Devon) and he's still doing business.  Still £50 inc. return P&P.

 

I've got mine to strip down and test but then I'll be giving him a ring to confirm my dead one is on it's way.

 

 

Dmm

[dapleb]

I still have a pre fried one if you are in a hurry and want to send that as a core and then send me your dud.

[dmmsta]

I still have a pre fried one if you are in a hurry and want to send that as a core and then send me your dud.

 

Train ticket has already been bought, so not in a rush...munchos thanks for the offer tho Mr Badger man.

[Aly86]

Next step.

 

I have bought a new stator. The 3 white wires which come away from the coil will need to be soldered on to the connectors, which fit in to the plastic housing. Can any one tell me if it matters which white wire goes in which space in the plug and if so how do I differanciate between them.

 

Many Thanks

 

[celticbiker]

Doesn't matter.

But rather than messing with the spades just cut the connector off with about 100mm of the old wiring still attached and then solder them to the new wires.

Do one at a time and shrink wrap each one as you go then SA tape the lot when finished.

[Aly86]

Well I am nearly ready to do some wall demolishing with my forehead.

 

Having replaced the stator, with a brand new one along with new white wires up to the connectors. I reassembled the bike started it up, however the the battery still does not appear to be charging.

 

At tick over I am getting around 12.44 volts,

5000rpm about 12.25 volts

Having switched the bike off after about five minutes the voltage returns up to about 12.65 volts.

 

The resistance between the 3 new white wires still does no fall within the range in the manual and is 0.6 ohms.

 

If any one has any further suggestions, they would be much appreciated.

 

Cheers

 

Aly

[leehenty]

regulator, check connector isn't corroded and it has a good earth. Measure any of the white wires resistance to earth there should be no continuity at all.

[Aly86]

Thanks, I'm a bit of a novice I'm afraid would you be able to tell me how to check the earth of the connector with my multimeter. I have checked the white wires resitance to earth and as you say there is infinite resisitance. I note there are new regilators on ebay for around £20, might be worth a gamble! Cheers

[leehenty]

sound like stator is ok as it should be it's new. between any of the white wires running should be around 25 volts AC at idle, so regulator next.

Incidentally, have you measured the old stator white wires to metal ring in the middle ? Before you chuck it might be a good idea.

[tdm92]

Well I am nearly ready to do some wall demolishing with my forehead.

 

Having replaced the stator, with a brand new one along with new white wires up to the connectors. I reassembled the bike started it up, however the the battery still does not appear to be charging.

 

At tick over I am getting around 12.44 volts,

5000rpm about 12.25 volts

Having switched the bike off after about five minutes the voltage returns up to about 12.65 volts.

 

The resistance between the 3 new white wires still does no fall within the range in the manual and is 0.6 ohms.

 

If any one has any further suggestions, they would be much appreciated.

 

Cheers

 

Aly

 

0.6 is the magic number.  I got that on my old stator and as it is outside all recomendations in links above and in the Haynes manual, I ordered a new one.  Arrived today and tests at 0.6 ohms.  Unfortunately, having removed the old one for visual inspection based on the advice that it was bad, I now have to decide whether to put it back on (gasket, oil etc) and sell the new one or put the new one on and swallow the loss.

 

Anyway, for info, a NEW STATOR READS 0.6 OHMS across all combinations of the three wires for a Mk1 3VD.

[Studley Ramrod]

I noticed when checking resistance with my multimeter, it takes a good few seconds before the reading settles.  Might be worth trying again and holding the probes in place for 5 seconds or more ?

[tdm92]

I noticed when checking resistance with my multimeter, it takes a good few seconds before the reading settles.  Might be worth trying again and holding the probes in place for 5 seconds or more ?

Thanks Studley, held longer and readings dropped to 0.5.  Then I had an idea: I put the meter pins together and got a steady 3.  5-3=2 which is close (to 1 decimal point) to Haynes.

 

The new stator is now mounted in the casing and will be assembled tomorrow with a new reg/rec.  Expensive learning curve. 

 

All back together with a new RR98 reg/rec aswell.  Charging! 

[MarkyMark]

In discussion with various members a number of these stator failures have happened after a service. (oil change).

 

I recently stumbled accross a tip:-

 - soak the filter in oil as this ensures full flow from the off.

 

Does anyone with more engineering nous than me think this is a potential explanation - i.e. why the top of the stator burns out - could it be that not enough oil is flowing to cool the stator immediately after a service.