Generator

[Dizerens5]

A little advice please...I'll soon have to replace brushes and brush-holder on my R65 generator. This means removing the stator housing and separating it from the stator itself. An old posting reported that this has to be done with care as the stator is often a tight fit. Ok. But two things I don't understand: how are the stator coils wired to the three-pin connector? Does the connector detach, or what? And just how do I remove the little parts called anti-rattle pins in the parts list? It looks as though they may be hard to shift and maybe even harder to get back in exactly the correct position. Is that right? Thanks.

[Bob_Roller]

The wires for the stator just pull off of the terminals on the stator .

The anti rattle pin, is just a roll pin that is pressed into the timing cover, you don't remove it, it just prevents the front cover from vibrating .

What you need to note, is which terminals the two wires for the brushes are on .

The black wire needs to be on the terminal that is insulated from touching the stator housing .

You'll see what I'm talking about when you get the brush holder off .

There are washers and spacers made of micarta/phenolic material to prevent one bolt from touching ground .

If you get this wrong, the alternator will not work, the voltage from the regulator will go directly to ground and not through the rotor .

[Dizerens5]

Thanks Bob.

[Dizerens5]

I've taken a close look at the generator. It's left me a bit puzzled, can any of you electricians shine some light? I have two wiring diagrams, one from the handbook and one from the Haynes manual. Their layouts are different but they agree that all four leads from the stator coils are black-insulated. Not on my 79 they aren't. The three from the 3-pin connector are clearly yellow, yellow/white and red/white. It looks like the original wiring, neat and tidy, and quite heavy-gauge. Does this mean something I have to watch out for?

[Barry]

The alternator is a 3 phase device and in an alternator at least the order of connection of the 3 heavy wires does not matter. This is why they are often all the same colour.

[Bob_Roller]

Looking at a wiring diagram, there are 4 wires, three are 2.5 sq/mm cross sectional area, then one is 1.5 sq/mm in area .

The larger diameter wires go on terminals W V and U .

Doesn't matter which terminals you choose out of those three, the alternator will work .

The smaller wire goes on terminal Y .

[montmil]

What Barry says. You can remove the three wires -no matter their color and orientation- and replace them in any order. All same, all same.

As far as the stator being a "tight fit", yes. It needs to be positioned correctly to properly function with the rotor. Close but not contacting.

Remove the attach hardware and, if need be, do a gentle tap with a small, hard rubber or leather mallet on the stator's frame. That'll loosen the stator and you can pull it straight out from the rotor.

All this just to get to the aft brush holder...  

[Dizerens5]

Yes what a hassle just to replace a couple of brushes. Our airheads are not always as low-maintenance as we like to think. Makes me quite nostalgic for my old Lucas 6-volt dynamos!

[Bob_Roller]

But you don't replace them that often, I replaced the originals on my '81 R65 in 2001 and 55,000 miles .

I believe new brushes are 14 mm long and recommended replacement at 7 mm in length .

[Dizerens5]

Anyone like to know what happened? The stator housing came off easy, this let me pull the brushes out. They measured around 10 mm (depending where you measure) and when in place, poked out by about 6 mm with plenty of spring pressure behind them. So no need to replace them yet. This wear seems to agree with the original (carbon-black) brushes being still in place at the 44,000 miles on the dial. This just might be the genuine mileage as I know some of the bike's history back to about 1990 and it does not seem to have been much used. Anyway it would have been difficult to change the brushes as although the stator came away from its housing with no problem, the two components will not separate by more than a few mm., certainly not enough for access to the brush-holder nuts. This is due to the wires from stator coils to 3-pin connector, they have no slack at all. I think the only way to go further would be to unsolder those wires, and solder them back afterward. Quite a tricky job and one needing very careful cleaning due to oily deposits all over. One good outcome: I could clean up the slip-ring which was very sooty.

[Dizerens5]

Btw to remove the stator housing it's possible to get both springs out of the way, hooked up on the edge of the brush-holder, but quite difficult for the inner brush. You need a very small screwdriver to hook the spring up, and a good light!

[montmil]

So everything is all right within the rotor and stator assembly? No problems with charging?

[Bengt_Phorqs]

Yes what a hassle just to replace a couple of brushes. Our airheads are not always as low-maintenance as we like to think. Makes me quite nostalgic for my old Lucas 6-volt dynamos!  

Are you quite mad?  The Lucas system is a devil spawned nightmare!  Simple yes, but so very unreliable (very much akin to my youngest daughters first boyfriend).  Glad that it all worked out for you.

[Dizerens5]

Yes it all works fine again. 13.5 volts at 3,000 rpm. I don't totally agree about the dynamo, I never had any bother at all on a series of 50s dynamo-and-magneto rigs. I think the bad Lucas reputation is based more on their 6-volt alternator kit, which was garbage and caused me mucho hassle. Their follow-on 12-volt equipment with 120-watt brushless alternator and Zener diode regulation was far better but it was too late!

[georgesgiralt]

Humm
I remember having changed the brushes on the R65 generator very easily. I did do it without removing the stator from the bike.
If you know how to solder, it's a piece of cake...