Test for the alternator

Ok I have good news and bad news. I pulled off the cover to the alternator and started to remove the brushes. I got the 2 screws off and my wife called me to answer the telephone. One brush is 12 mm long and one is 3 mm long. So I need new brushes. The ring on the alternator was fairly clean. Some oil on the outer part (copper wire with tape outside of the ring) The ring had a few ""skid marks" on it with clean copper sections in between. I am ordering new ones from Oldbikebarn. Am still looking for the glass paper.

Here is the bad news. I don't remember which way they go back on. I am assuming the brushes face toward the ring, but I could not remember how they looked when I took them off. The brushes spring out toward the ring, like a small block of carbon it looks like.

I took this time, since it was down, to replace my fuses with inline ones. I will have to work some more on that one, since when I put the seat on, it ripped off the fuse for the turn signals.

 

By the way, Thanks Robert for that web site. That was the one I was looking for. I check out the regulator and all of the diodes checked out OK.

 

Always glad to help where I can. Very hopeful you get this alternator item ironed out. I could use some brushes as well, ought to order them up. Where have you sourced your brushes from and how much is the shipping?

 

Old bike barn. I called because I could not find them (Was on hold forever) On the web site, you go under Starter Brushes. Once you pick your model, starter brushes are on top, alternator brushed are on the bottom of the list. 24.97 was the cost. Total with shipping is $33.00.

 

RickCoMatic ... called-it! Brushes. Now your battery will be getting a little juice!

I'm pretty sure that the new brushes will only go in their housing one way. They are both very slightly rectangled. The mount ought to have a "Footprint" ... or "Pigtail memory." If not; the mounting plate has to line-up such that the two brushes will make contact with the two rings on the alternator.

You can give some of your wifes copper cleaner a shot. Or, you can try some Mothers polish. Either might work if the scortch is more of a tarnish than a severe burn.

Clean off the whole works, in there, with a spray can of Electronic Parts Cleaner or Contact Re-new.

I'm hoping it cleans-up nice without a spot on there that's burned off. If that's the case ... you'll need an alternator rotor; because the "spot" will cause the new brush to arc and you'll be way up the river if that happens.

Finger crossed; everybody.

 

Thanks Rick, I have copper cleaner and Mothers and contact cleaner. I am not sure how long it will take for the brushes to get her but this electrical work, installing new fuses in my Maxim and trying to get my son's CBR600's carbs drained, I will be pretty busy the next few days. Pity too, it is perfect riding weather and me without a running cycle.

 

Have you tried taking your one good brush to an ACE Hardware (or similar DIY place) and comparing to their parts bin? I'm fairly certain you could score a set close enough to perform for just a few dollars. Wouldn't want you to miss out on valuable riding time.

 

Well I learned some electrical stuff on this one. Now I know that the brushes CAN cause a voltage surge and it can do it with the R/R working well and not burn it up. Got a little more faith in Yamaha's R/R's now!

 

If you're stuck, you can pull the carbon post out of the center of some "d" cell batteries and shape it to fit.

 

Or ... buy a really shabby-looking alternator cover off ebay for short money and roll the dice on the brushes and holder being good.

 

The brushes finally came. I put them in last night and she runs great. Between the new brushes and my changing out the fuse box, the headlight is much brighter. And my turn signals really flash. Now I need to look for a new turn signal switch that will really self cancel. The only downside to this is now I have a new battery that I really did not need.

Thanks for all of your help.

 

I'm carving a notch in my gun.

Nice work on the brushes. Nothing like having to stick a new set of brushes in the bike. I'll bet you could sell rebuilt brushes!

Returned to flight status!

Rick Massey

 

Wait wait, so the starter brushes give charge too? I thought it was just the alternator stator responsible. I'm a bit confused now. My bike isn't charging my battery as I ride either. It runs fine, but starts horribly as a result of this (I do have a new battery that I charged up initially). I have to charge the battery almost every day before I go riding so as to make sure I'm not hill starting the bike at some point in my day. It isn't always a guarantee even. Anyway, perhaps someone could be of some help?

 

Battery losing charge / Not charging.
Check system.
Hook-up Voltmeter to Battery.
Battery @ 12V (or above)
Start Motorcycle. Monitor Voltage at Battery.
Battery low. Charge for 12V Min test value.

Start bike.
Watch the Voltage at the battery. Reading should be above 12V.
Rev-up engine watching Voltage at battery. Voltage should increase to 14V when engine reaches 1,100 rpm. As engine rpm's are raised the voltage should rise; too. At 2,750 or so ... you shoud be up to 14.2V

The Voltage should rise from 14V to 14.2 (maybe 14.3) as the rpm's are increased ... and then remain constant at 14.2 (above 14) but, STEADY beyond 2,750.

No charge.
Check the alternator brushes and connections.
Brushes bad; replace.
Brushes Good. Check Voltage Regulator.

(Since you already stated that you "Jumped Started" it ...
Inspect:
The terminal ends inside the plastic quick-connection -- Voltage Regulator to wiring harness. Look at spade connected to RED wire.

Plastic looks overheated, melted or spade inside this connector looks blued. Red wire appears to have been subject to heat ...

Write a nice Obituary for your Voltage Regulator.
Remove Voltage Regulator from motorcycle.
See how far you can throw a fried Voltage Regulator.
Cuttent World Record: 87 Yards 2 Feet 3 Inches.

 

I can't find a listing for alternator brushes on oldbikebarn.com. Any help?

 

Are they short out-of-specs?

You can measure how much of the brush is remaining. There's also a line on them ... like "Wear bars" on tires.

I don't know if they are available in the aftermarket. The brushes might be something you need to go to a Dealer for. Some people fabricate new ones from the wide assortment available for power tools ... and "shave" them down to fit the slightly rectangled shape needed for the housing.

Needing brushes every twenty years or so ... I'd say pop for the Genuine Article!

Google: Zanotti Motors --- they're an online Yamaha Dealership offering a real discount for ordering from they're web site.

 

I just checked the alternator brushes on my bike, and they aren't short. They are right around 10 mm, or maybe even a little over. I checked the voltage at the battery when the bike's running, and it's reading 11.3 at an idle and 11.5 at roughly 4000 rpm. I don't know what in the system could be the trouble, but something certainly is. I don't have an way of checking resistance or anything, so I suppose I'm just looking for some ideas. Is it possible that with correct length brushes the alternator may still not be giving out enough power?

 

Did you check the plastic quick-connection where the Voltage Regulator is attached to the wiring harness.

Let me know what the condition of the inside of that plastic connector looks like ... particularily the condition of the spade connected to the Red wire, the plastic red covering on the wire near the spade terminal ... and the condition of the connection block.

I'm betting a dollar there's some evidence of overheating. You probably need a new Voltage Regulator.

 

Good news annd bad news. I broke the fuse for the ignition, and, because the dumbass before soldered in teh fuses, I had to bypass it by tying it together with copper wire. Low and behold, the amount of voltage the battery recieves has gone up over half a volt at low idle to around 12.1 or 12.2 volts. Which means, sadly, that I have to replace my fuse box or at least do a bypass on all my fuses for the time being. So, I found the problem.

"Hazaa's are in order."

-Futurama's Professor Farnsworth

 

Select any prize you like off the bottom shelf.

You'd have gotten a prize off the top shelf ... but, soldering the copper wire across the terminals and leaving the ignition circuit unprotected by a fuse cost you some points.

The judges took into consideration your good intentions to place some temporary inline fuses in there until you install a new fuse panel.

www.wirewerks.com Get the 6-place one for less than 10-bucks!