Graybeard,
Welcome to GSR.
Thanks for the impressive information and testing/observations you have listed.
Each of 2, 3, & 6 are things that indicate a bad starter (probably bad worn down brushes).
Uaslly someone says "it will not start", then have to determine/verify that they mean it will not turnover, then ask for them to check these things that you mention in your 2, 3 and 6.
Yes, starters can be rebuilt. Can get a brush kit from Stockers (or elsewhere), although you may not know if you need the 4 brsuh type of kit or the two brush type of kit.
Maybe you can take the cover off the starter motor, and look at back end of the starer motor to see what maufacture (Misubusho or Matsuthata or Ginsue or something or other) and can find that on the Stocker website. Any particulkar model or year of bike may have one of two or three manufuactures of starter motor. They all interchange, but have different types of brushes inside.
Or maybe you will decide that if you are going to the effort of taking out the starter motor, that you want to just reinstall a complety rebuilt starter right away, rather than take out yours and fuss around trying to rebuild it yourself.
Plus if you rebuild it yourself you are only replacing the brushes, and you have to also machine down the commutators (I did by hand by spinning with drill motor and holding with emmory cloth against the commutator bars).
http://www.thegsresources.com/_forum/showthread.php?t=131785
Posting with some photos.
So, compare cost of a rebuilt starter compared to a rebuild kit. Decide how much you want to fuss with rebuilding the starter motor and then if you want to try it, will need to find out what type/manufacture of starter motor you have to get the right kit.
I have used Stocker for rebuild kits and for rebuilt starters. One intersting thing they do with the rebuilt motors is the cost includes the shipping for you to send back your original (or at least that is how they did it a couple years ago) and they send you the return pre paid label. They dont charge the core charge unless you dont send them yhour original.
Hey, wait, oh wait.
Are not suppose to give any advise untill you post photo of your bike.
(joking)
Where on this planet are you and your bike located? (Goto User CP and add that to your profile and signature line, will then show up on every posting)
Again, welcome to GSR.
<<<Later note
http://www.stockers.com/index.php?oc=1
Enter in suzuki motorcycle, GS850
and see a listing of differnt starter motors and differetn rebuild kits:
Starter - Suzuki Motorcycle Type:Remanufactured Replaces

enso Stockers #:SS-16
Retail Price: $224.95 Your Price: $149.95 Core Deposit: $50.00
Starter
Fits: Suzuki Motorcycle
1980-1982 GS550
1981-1982 GS650E
1980-1983 GS750E
1980-1983 GS850G
1980-1982 GS1000
1980-1984 GS1100
12 Volt, CCW, 9 Teeth
And here is another one
Starter - Suzuki Motorcycle Type:Remanufactured Replaces:Mitsuba Stockers #:SS-5
Retail Price: $209.95 Your Price: $139.95 Core Deposit: $50.00
Starter
Fits: Suzuki Motorcycle
1980-1982 GS550
1981-1982 GS650E
1980-1983 GS750E
1980-1983 GS850G
1980-1982 GS1000
1980-1984 GS1100
12 Volt, CCW, 9 Teeth
Seems like the list should include more models/engine size. I thought they were the same for about any 4 cyclinder GS.
THis from Dennis Kirk Catalog for a Ricks starter
Ricks Motorsport Electrics Starter
Dennis Kirk Part #: 202100
Manufacturer Part #: 61304
Your Price: $175.99
Low Price Guarantee (details)
- Part 202100 fits the following machines:
- 1978 Suzuki GS1000
- 1979 Suzuki GS1000
- 1978 Suzuki GS1000E
- 1979 Suzuki GS1000E
- 1980 Suzuki GS1000E
- 1980 Suzuki GS1000G
- 1981 Suzuki GS1000G
- 1980 Suzuki GS1000GL L
- 1981 Suzuki GS1000GL L
- 1979 Suzuki GS1000L
- 1979 Suzuki GS1000S
- 1980 Suzuki GS1000S
- 1982 Suzuki GS1000S Katana
- 1980 Suzuki GS1100E
- 1981 Suzuki GS1100E
- 1982 Suzuki GS1100E
- 1983 Suzuki GS1100E
- 1983 Suzuki GS1100ES
- 1982 Suzuki GS1100G
- 1983 Suzuki GS1100G
- 1982 Suzuki GS1100GK
- 1983 Suzuki GS1100GK
- 1982 Suzuki GS1100GL L
- 1983 Suzuki GS1100GL L
- 1980 Suzuki GS1100L L
- 1983 Suzuki GS1100S Katana
- 1978 Suzuki GS550
- 1979 Suzuki GS550
- 1980 Suzuki GS550
- 1978 Suzuki GS550E
- 1979 Suzuki GS550E
- 1980 Suzuki GS550E
- 1979 Suzuki GS550L
- 1980 Suzuki GS550L
- 1981 Suzuki GS550L
- 1982 Suzuki GS550L
- 1982 Suzuki GS550M Katana
- 1981 Suzuki GS650E
- 1982 Suzuki GS650E
- 1977 Suzuki GS750
- 1978 Suzuki GS750
- 1979 Suzuki GS750
- 1978 Suzuki GS750E
- 1979 Suzuki GS750E
- 1980 Suzuki GS750E
- 1981 Suzuki GS750E
- 1982 Suzuki GS750E
- 1983 Suzuki GS750E
- 1983 Suzuki GS750ES
- 1979 Suzuki GS750L
- 1980 Suzuki GS750L
- 1981 Suzuki GS750L
- 1983 Suzuki GS750S Katana
- 1982 Suzuki GS750T
- 1983 Suzuki GS750T
- 1979 Suzuki GS850G
- 1980 Suzuki GS850G
- 1981 Suzuki GS850G
- 1982 Suzuki GS850G
- 1983 Suzuki GS850G
.