generator brushes

[lawnboy]

How much do the brushes effect charging? Rotor seems to test ok as per manual but when I check voltage at the battery with the bike running it jumps all over the place. After 5 to 10 min of running at various rpms voltage drops to 10 or so.  Then if I pull the battery and check it after 10 min it gets back to 12 volts.   AGM battery that's not that old and I re-charge it before testing. Running vintage smoke ignition and rick's regulator/rectifier. I cleaned the face of the rotor up with 600 but I'm leery of the brushes because they aren't square to the face of the rotor.

D3rf

[m in sc]

they need to be good, if you aren't sure, replace them. also check all connections everywhere are clean and tight. sitting at an angle means they are worn, and might 'stick' in the holders giving intermittent connection as they bounce around

[lawnboy]

Thanks.

Ordered a pair of on my lunch break. Should be here wed.

[pidjones]

How much do they effect charging? They carry field excitation current to the field windings. Current through tge field windings creates the magnetic field that moves the electrons in the stator that creates charging current. No field, no charge. That's how the regulator controls charging.

Yes, new brushes square to the slip rings with proper brush pressure and smooth, clean slip rings are very important to charging. I usually polish to at least 2000 grit, sometimes finer. Carbon (the brushes) is much dofter that the copper slip rings, and rough slip rings will wear out brushes rapidly.

[m in sc]

if they are angled, they are worn on the side. this means they can 'hang' in the brush holder and not make consistent contact w the slip rings.