Starter brushes wearing.

[KEITH KRAUSE]

My '79GS1000E has 117,000 mi. The starter motor is original and never been opened. It always starts easily unless the battery is getting old(3-4 yrs.) When the battery is this low the bike does 'kick back' once in a while
making a 'CLACK' sound,but still starts pretty quick. As soon as I replace the battery it's like new. After reading other topics I'm curious about the condition of my brushes. My manual does'nt say much about them except
if they are too worn it will lead to hard or no starting.
I don't want to take the starter apart because (going on the bikes past)
it's time to change the battery. But the brushes are suspect. So my questions are: if the brushes are going bad is it obvious?(hard starting becoming worse and worse and eventually just a 'click'?) And if the brush
(positive or negative)wears until it is actually gone, would the commutator
get damaged? Would the bike still be able to start even with a brush
completely gone? Thanks for any help! KK.

[gs650gt]

brushes

I just opened and cleaned the starter motor of my gs650gt after 215 000 kms and the brushes were still within the limits, no problem at all.

the starter motor was quite dirty from inside so I just cleaned it, though I haven't had any starting troubles so far.

[Clone]

As your brushes get shorter, at some point they will arc. This will damage the baseplate. Usually if the contact area (can't remember the correct term, where the brush contacts the armature) is getting a carbon build up and pitted, it can reduce your starting power. You would think it is the battery, but maybe not. Opening up a starter is no big job. If you are concerned or curious, pull it out and take a look. Clean it out and put it back if the brushes are good. if not throw in a new set.
once the brush is worn away, you will just get a click, the bike won't turn over.

[dgeorge]

Keith, I just posted a question yesterday about starters, and Billy Ricks posted a link to a site that has brushes very resonably priced. If you need them you might want to check out the link that is in my post, ? about starters. Hope this helps.

[mcconnell]

If the brushes wear all the way out, the commutator will be damaged.

Do you ride in such a way that you ride far enough to empty a tank of gas with each start? 117k is real good life for brushes. The few original starters I went into had very rough commutators that wore brushes quickly. After machining the commutator on mine at about 35k, the brushes are wearing considerably slower. The starter on my '83 is actually easy enough to get out that I removed it a few years ago just for a brush inspection. Just keep track of where all the washers go inside the starter.

[Anonymous]

Brushing away the blues....

I've torn into failing starters & what I note is that the brushes actually have what you might call a 'Travel stop'. They have a crimp on the channel that guides the brush...keeping it place as it wears closer and closer to the commutator. The little piece of tin that's attached to the end of the brush fouls on the crimp and stops the brush from moving forward under spring pressure. So the brush now is being pressed lighter and lighter against the commutator until it just has a small gap and winds up arcing rather than actually conducting power to the commutator.
Makes sense ...you don't want springs and wires spinning around in there once you've run out of brush. But by then the commutator is so deeply grooved you don't have enough left to machine or sand down flat.
Rick.......

[mcconnell]

Though it's been over 10 years, I'm pretty sure at least one of my springs hit the commutator, damaging it. Fortunately, since there's no brush left, only some of the braided copper that was attached to the brush, the starter barely works when you get to this point, limiting the damage. Getting a bad case of CRS on some of these things, though. Pull the starter and check the brushes.

[KEITH KRAUSE]

Thanks for replies!

Thanks guys! I'll do a 'preventative maintainence' check to be safe. Seems like our starters may vary in design. Some wear out the brushes and just quit working, others allow the brushes to cause more damage while still starting the bike. KK.