Troubleshooting a Starter Motor (Pictures Included)

[gerpena]

My starter wasn’t turning when I tried to start my bike so I was told to take the starter apart and clean it from the inside. I already tried a new battery.

Inside the case it was quite dirty (about a half a cup of black residue) so using a damp paper towel I carefully took it apart and cleaned it as best I could. I also noticed 2 of the 4 brushes on the brush terminal assembly are broken and disconnected from their wires. The other two are fragmented and chipped. Here are some pictures:

http://tinyurl.com/b9rt2
http://tinyurl.com/cgvro

I followed my Clymers manual and did some tests with my voltmeter on the starter—it seems to be working fine as far as appropriate resistances go. The brushes seem destroyed however.

My questions are as follows:

1. Where can I find a replacement for the brush terminal assembly for my 1983 cb550sc for a good price?
2. How do I dress the commutator so it’s smooth? I have limited access to tools but want to do things the right way.

[gerpena]

what you are doing when you dress the comm. is cleaning it up and returning it to flat smooth condition, you will use a file, which encompasses the entire surface of the comm. as it rotates (chuck the comm. end shaft, up into a drill motor )press the file against the comm. and file away you will have to clean the file as the copper builds up ( file card or wire brush )follow up with scotch brite for a fine finish.

what type of file are we talking about here? can i just use sandpaper and a regular drill? what do you guys think?

[Gummiente]

what type of file are we talking about here? can i just use sandpaper and a regular drill? what do you guys think?

You could use fine grit sandpaper, but the problem there is that you won't be applying even pressure across the commutator surface which will result in uneven and rapid wear on the new brushes. Get a smooth lathe or mill file, preferably single cut (ie: the file teeth are only cut on one angle) - it has one edge that is smooth, place that edge towards the windings so that the file won't get caught in them if you wander too close. Only remove enough material to make the commutator surface smooth again. Check to make sure there is still insulation between the commutator segments, these tiny strips should be flush with or below the surface of the copper segments.

As for the brushes, take one of the good ones to any automotive electrical repair shop (usually found in the Yellow Pages under "Automotive - Alternator/Starter Rebuilding") and they should be able to find replacements that will work.

[gerpena]

Get a smooth lathe or mill file, preferably single cut (ie: the file teeth are only cut on one angle) - it has one edge that is smooth, place that edge towards the windings so that the file won't get caught in them if you wander too close. Only remove enough material to make the commutator surface smooth again.

Thanks for the great advice Gummiente. I can do all this with a regular hand held drill right? coz thats ill ive's got.

is it better to shell out 40 bucks and get a new brush terminal assembly from honda or should i just go to the electrical shop and have them set me up with something that will work?

thanks!

[Gummiente]

I can do all this with a regular hand held drill right? coz thats ill ive's got.

Well, I wouldn't recommend it... it'll be hard to hold the drill in one hand and the file in the other and still do a good job. You need to have a light touch on the file and be careful that it doesn't wander into the windings and wreck them - the only way you could do it is if the drill has an adjustable speed lock and it is clamped in a bench vise to keep it steady while you hold the file. Before you attempt it, why not take the armature and the brushes to an automotive alternator repair shop and see how much it would cost for them to do the work for you.

[Henriettaah]

Is sourcing bike parts hugely different to car parts? - I had a dodgy solenoid in the car which gave up recently, and a replacement starter motor was only about $20 used.. Removed and replaced it myself so wasn't a major cost. Forgive me if I am making pointless suggestions, gerpena