Here's some of my notes from Charging System Checkout, in case you do not yet have these ...

12. Generator Brushes Assembly: Dismantle, Cleaning, Repair

1. The brushes holder and related parts can be dismantled without removing the gen from the bike. This is useful because, in my [limited] experience, if the gen light is coming on then one or both of the brushes is probably sticking. This can be easy to fix, and can be done at the side of the road if necessary, as in this pic ...



However, as PG adsvises, it is far better to do this in a clean environment.

I am writing this from memory, not while doing it. I think i have the removal process right.

Remove gen end cap. Remove the bracket and brush cover strap. Remove the commutator end cover. There are 3 screws visible. Two just hold the brushes to the brush holder; these do not need to be removed. The third screw attaches a wire from inside the gen to the brush assembly. Remove this screw. Now the brush assembly can be removed.

Usually it is quite dirty in there so at this point i use a spray can of electrical contacts cleaner to clean up the mess.

The brushes will spring out of the brush holder. They must be each longer than 1/2 inch else replace both. Reinstall each temporarily and work them between thumb and finger to see if there is any binding.

To re-install brushes in holder use long twist ties from the kitchen. Pick out the twist ties after the holder is re-installed.

2. To remove the gen from the bike: Disconnect the wires from the A and F terminals; remove the two bolts from the gearcase side; raise the inner end toward the 11:00 o'clock position, lower the outer end toward the 5:00 o'clock position, and remove carefully.

For the rest you really need a manual. The FM is very good. It is usually not necessary to remove the gen drive gear - this requires a gear puller to remove. The rest of the gen dismantles quite easily.

Once opened up you can do more cleaning and inspection; again using the spray can electrical contacts cleaner.

The FM contains a number of tests that you can easily do once it is opened up: field coil test, shorted or open field test, grounded armature test, and open armature test.

The shorted armature test requires special equipment which a shop would have [a growler]. Doing actual repair may require special equipment such as a lathe, and perhaps experienced hands.

 

I have the generator apart, everything is very dirty (have my can of cleaner for that). The brushes are longer than 1/2" as per the FSM, but one of the springs was on crooked and the brush is ground at an angle. Is it still servicable?

 

Took generator apart and cleaned everything, got back together and still no charging. The generator light is now on, which was not before. When I tried to polarize the generator, it made no "thud" sound as the contact was made. Also the positive lead that is connected to the brush terminal had some exposed wire due to insulation being worn off.

 

When you polarize you should get the spark and the gentle clunk. But i do not know what would be wrong with the gen if you do not get these.

I would take it apart again, check everything, put some heat shrink on that exposed wire, and try again.

Before installing try this bench test ...

1. connect a jumper from the "+" battery post to the "A" armature terminal on the gen.
2. Connect a jumper from the "-" battery post to the "F" field terminal of the gen.
3. Now take a third jumper from the "-" battery post and touch it to the case of the gen.

If all is well the generator will run like an electric motor. With the gen gear pointing away from you the rotation is clockwise.

Don't try this with the generator on the bike.

I do not know if this is a complete test. If this test does not work then the gen needs service. I do not know however, if success means that the gen will work on the bike.

I always run this test before re-installing.

 

Your next step is to take the generator to a generator shop and let them put it on a growler to test the armature for shorts in the wiring.
Also check the field coils.

If you do not have a generator shop or a growler then check the armature using a battery and ammeter as described in the factory service manual.
pg

 

+1...if it wore through the insolation...you have been likely running it with a dead short.

 

Also check the fuse that feeds the generater that might have shorted to ground also I have seen that also

 

I am going to further test the generator tomorrow but had a question about the procedure. When it explains to Connect an ammeter and battery in series with test points, does this go something like this: Battery + to red probe on multimeter, black probe on multimeter to test point and then run a ground from battery - to generator frame?

Had the gen glanced at by indie shop. It was able to be polarized and spun like a motor when electrified. It read 0 amps when hooked up to an electric motor to turn it though. Looking for a short and was also told to check the insulation.

 

duplicate delete

 

Spent more time taking apart and inspecting the generator today. The picture below is of the armature, I noticed a burnt spot and when I inspected it the little "cap" of the armature plate crumbled off. I also noticed more were loose.


I got heat shrink tubing around the positive lead that I mentioned was exposed before. Once I get a new terminal and either repair the armature or get a new one It will be time to try again.