Generator brush replacement help needed.

[Jimbo W]

My 1980 Special 2 has the same brushes as when I bought it 18 years ago so thought I'd fit new ones. When the replacements arrived from Yambits one came apart in my hands so Yambits sent me a second pair (they do excellent service). Now I come to fit them, 2 weeks later, I just can't figure out how they go. Obviously the carbon bit slides into the tunnel but the cranked brackets have got me beat. Also which brush screw goes into which hole? Could someone please post a photo (the Haynes photo shows the earlier model & is terrible quality anyway). I know, I should have waited until I had the new ones before removing the old ones.

 

[gggGary]

Note the bakelite rectangle goes under the metal Z bracket, and the wire wraps around to the top side.
The bakelite rectangle is out of position on the top RH brush in this pic, oops. The LH is in it's correct spot.

View attachment 228931

 

[Jimbo W]

Great, many thanks, I'll have another fiddle asap. I have to say though, I'm still not quite "getting" it. Fitted carbon brushes to a washing machine once but never a m/c!

 

[5twins]

Gary, on the '80 and later brushes, the inner is fed the constant 12 volts, the outer gets the regulated ground from the regulator .....

A few more tips - the wire wraps around the outside of each bracket. There is a slight "channel" in the brush block for the wire to run in (you can see it if you look closely). To make wrapping the wire around easy, push the bakelite insulator rectangle down against the spring, compressing it against the brush. That will expose the bare wire so you can wrap it around. Also, the rectangular insulator only fits under the bracket correctly one way. Have it turned wrong and it will hang out the sides. Here's the way my '78 came to me. The left (outer) brush wire was routed wrong, over the top instead of wrapped around the outside .....

 

[5twins]

One more thing - the screw lengths. Make sure you get them right. Put a 12mm long one where an 8mm one is supposed to go and it will hit the rotor face and gouge into it .....

 

[Jimbo W]

Managed it, pretty fiddly job but got there. Thanks very much for the help - wouldn't have figured it by myself. Got other running issues to sort before I can test it but am hopeful.