Dimming Headlight - Alternator Brush Question

My bike has a dimming headlight at idle, it gets very low than will brighten up then will dim and so on and so forth...so per prior posts I took off the alternator cover to inspect the brushes. I can see the wear line on both brushes, one brush looks brand new the other brush is worn down close to the line but still has a a little distance to travel. Is it normal for them to wear down at a different rate like that? Is that the source of the dimming than brightening cycle I experience at idle?

I already have the new brushes from chacal, but I can't get the dang screws off and already stripped them a bit. I stopped before making them any worse....just get a bigger screwdriver, suggestions appreciated...

 

pabstblueribbon it is normal for the brushes to wear uneven if you look at the rotor at the two round rings and think about it for every 1 revolution the rotor makes the larger ring will have traveled a further distance so you get more wear on that brush also as the brushes wear the spring will put less pressure on the brush. It also helps to keep your battery charged up with a battery tender when your not using the bike everyday or you do a lot of stop and go riding as the bike does not charge much at idle. I use Brasso to clean the rotor some guys use a fine sand paper or scotchbrite as for the screws you need to use the right tools the screws are not U.S. standard Phillips heads they are JIS heads. Copied from XJ forever catalog:
individual JIS-standards Screwdrivers:

The #2 and #3 fit the most commonly used size screws on the carbs, gauge clusters, etc.

HCP5900 Aftermarket size #1 JIS-standards SCREWDRIVER, for m2-m4 sized screws.
$ 9.95

HCP5901 Aftermarket size #2 JIS-standards SCREWDRIVER, for m3-m5 sized screws.
$ 11.95

HCP5902 Aftermarket size #3 JIS-standards SCREWDRIVER, for m6-m8 sized screws.
$ 13.95

HCP5903 Aftermarket size #3 JIS-standards SCREWDRIVER, for m8-up sized screws.
$ 16.95
Heres a link to lens website just scroll down to section P:
http://www.xjbikes.com/Forums/viewtopic ... rt=75.html

 

much appreciated it, I'll get the appropriate screwdrivers, consider it a long term investment for the bike. I'll get in touch with chacal.
Thanks waldo

 

Keep something in mind: At idle, the alternator hasn't really "kicked in" so you're running primarily off the battery. The alternator doesn't come up to full output until you hit about 3000rpm, and dosen't really have any effect at all below about 2000rpm.

That being said, the alternator needs to be in good shape to keep the battery fully charged; but alternator brushes alone won't make the headlight much brighter at idle.