wont accelerate, coughs and stops...?

[Bob_Roller]

Did you remove the brush holder from the alternator to replace the brushes ?

If you did, there are insulating fiber washers that keep the hardware from the wire that gets it's power from the voltage regulator from touching ground .

It pretty much makes the alternator 'dead'/ no power output, due to the power that should be going to the rotor, is now going straight to ground .

[benlawlor85]

BOB YOU STAR!!!!

Thanks so much!

i had put both fibre washers on the front. so both terminals were going to ground.
Nice easy quick fix! thanks again!!


Ben.

[tvrla]

I'm having difficulty following this. More specifics are needed.

Here's the situation currently as I perceive it:

Engine and ignition now working fine.

Charging system isn't - Red Charge light is on and doesn't go out, even when the engine is revved about 2K.

Because the light is on, you know there's a current path to ground - the rotor isn't open, so no need to test the slip rings. The light being on tells you that the path to ground (for the charge bulb) is good. It goes through the brushes to the rotor and then to ground. The rotor could be bad (with a shorted winding) but you definitely know it's not an open winding.

When testing the voltage regulator, was the engine running and revved up to two or three thousand RPM?

We need to know exactly what conditions the tests were done under - engine running, RPMs, and stuff like that. Otherwise it leaves doubt as to what exactly is going on.

And I agree - make sure the battery is in good condition before going any farther.

[Sergeant_Joe]

Ta da!.........95% of the time it's an earth problem, this is yet another example of this rule.
in this case he left a felt washer off, earthing both posts out to the bikes body by the sound of his last post.
Glad it ended well for you mate.

[benlawlor85]

yeah silly mistake... made the same evening i mis-aligned the bean-can.  
Have new battery and HT leads arriving today. So that combined with now being kept inside should make starting alot easier.
I did notice that the spark seems to be alot stronger yesterday after i cleaned all the connectors on the bike. so am going to put of getting a new coil for the moment. But ill be sure to keep checking it.

thanks again
Ben

[Dave 2]

If you did, there are insulating fiber washers that keep the hardware from the wire that gets it's power from the voltage regulator from touching ground .
 

Bob, I went on to the Max Motorcycle's parts micro-fiche website and on the page for "Alternator, Individual parts" (12-0737) I did not find any felt washers. However on the "Cover" 11-1171 I did find a washer/gasket (2 required). Are these the ones you are talking about. I'm curious because I will be getting into that pretty soon on my LS. Thanks. [smiley=bmw_smiley.gif] D2

[Bob_Roller]

No, I don't see them listed on either illustration .

I even went to other displacement bikes and still have not found them .

The washer/spacers are phenolic/fiber material, not felt .

[montmil]

DaveTwo,

Those two small, circular gaskets used in combination with the timing case-to-block gasket are there to keep the timing case "flat" to the engine block. Evidently, leaving them off can lead to potential uneven seating of the timing case.

Some peeps just use bits of the used case gasket. The timing chain replacement kit that I purchased from Motobins had everything, including the two 'donut' gaskets that I would have missed.

Monte

[benlawlor85]

The fibre washes are used with a small cylinder washer too its very basic when you think about it (i obviously didn't) one terminal is grounded the other is live, the live one is isolated from the ground using the two washers and the cylinder shaped one. This isolates the bolt that attaches the brush housing to the stator.

Hope that helps.

Ben

[Dave 2]

This is a very interesting and helpful thread. when I begin to remove the alternator/brushes and the timing cover I will be on the alert for the

two washers and the cylinder shaped one. This isolates the bolt that attaches the brush housing to the stator.

so I make sure to get it back in the right order. This is not the first time that what I see on my LS is not what is represented in Clymer or BMW parts Fiches. This also makes me think that in the future when I do some wrenching I will continue my practice of photographing everything as I take it apart [smiley=bmw_smiley.gif]

[benlawlor85]

Dave2 thats so important. Take as many photos as possible and annotate you manual. I have the haynes manual and the wires that go onto the alternator are not listed to what colours go where. the other wire i always get confused with in the black wire that is paired with the blue wire that goes to the back of the diode board. it goes to the starter... i cant tell you how many times i have forgotten where that goes!

On a happy note. according to the tracking data my parts have arrived! So should have her working 100% this eve! :-)

[benlawlor85]

Hi all just for an update.
I had a couple of weeks of work with the plan of doing some winter walking in the Lake District.... but all the snow melted! So i thought great can get on with the bike.... but no i had to finnish the bathroom!! :-(
I finally got around to ordering the Coil and some NGK caps and leads. That was my first problem nowhere could i get the ends that go into the coil, the ones on the old BMW leads were messed up badly. I finally placed an order with http://www.autoelectricsupplies.co.uk/home
i also ordered some 4 way connectors as there is a bodge with a choc block under the tank works fine- looks crap. The HT ends i got were the crimp type http://www.autoelectricsupplies.co.uk/product/83/category/17  and they fitted a treat now when you pull the wire it pull the sheathing now the wire core, must be a plus over the BMW ones. Think i will re end the BMW ones i have and use as a spare. I also bought a tube of http://www.autoelectricsupplies.co.uk/product/827/category/154 seems to be better than the stuff i had bean using!
Sorry... looks like this is going to be a long post!!
So with the coil and leads fitted she fired first time! :-) but spluttered and stopped soon after! :-( I then checked some contacts both the big brown earth - cleaned and re-fitted then any connector that had brown or back in it, there was one three way and one two way. They were awful, even tho i cleaned etc the other day the contacts had had it. So i dis asembled and used the new spades i bought and then contralubed the **** out of them! I then also found teh fuel filters were very dirty so cleaned them (there are single use but i dont have any spares at the moment).
Fired her up, adjusted timing (as i removed the bean can to check to see if the missing shim was giving it any grief).

AND SHE IS RUNNING LIKE A DREAM!!!

So a big thanks to you all but  especially Bob who helped me with the alternator.
Now i can get back on with the fun bits... upgrades and accessories etc! :-)

Ben

[tvrla]

Excellent news! Another situation of dodgy connections, plugged filters and blocked sparks. Easy peasy!

I feel your satisfaction!