Gs parts interchangability

[Guest]

My old 1985 gs 850 started to fail charging the battery, as per the norm i tested and replaced the stator, the rec/reg, checked the wiring for damage or loose connections, fitted a new battery, checked and rechecked the charging circuit, tested the new components: im now at the stage that the only component not tested or replaced is the magnetic rotor; there is very little information published; various professional mechanics have offered sage words of advice "they dont go wrong" "so long as it's a bit magnetic it'll work ok" and "I've never seen a broken one in my 25 years"
I cant test the field of flux (magnetism) without the expensive equipment, but it should apparently be difficult to pull a spanner off, which it isn't
Heres the question, are the rotors from the later gs 500s the same size, do they fit the other gs models, will a 500 rotor fit my 850?
did/have suzuki cured the electrical gremlins with the 500 twin: many thanks Robbie

[Nessism]

You can check part interchangeability by using an OEM parts fishe such as the one on Partzilla.

Did you use a new stator or a used one? Did you rewire the charging system to bypass the factory wiring? What type of R/R did you use? A SH775, new stator, and rewiring the system should get it done unless the rotor magnets are falling off.

SH775 Install by nessism, on Flickr

[Redman]

rotor loosing magnitism is a very rare occurance.

one thing you should know is the rotor and stator prior to 80 where 12 pole and 80 and after were 18 pole, so cant interchange over that year boundry.

other than the stoatr itself and the r/r itself, two other common problems to be aware of are:
- good connection between stator and r/r
- r/r being well grounded. typically r/r mounted to battery box and its ground(black) wire landed on mounting bolt of solenoid, but that is also the battery box which is not well grounded to frame by its mounting,,, so is grounded bt blackwhite wire from bike wiring harness, but sometimes that is not a good ground. chrck it out, or add your own wire from ther to frame ir battery negitive .

maybe do the quick tesyt, and report votage with key off, and key on, and at idle and at 4000 rpm. let folks here evaluate that


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[Grimly]

They can lose magnetism, as can any permanent magnet.
The normal causes of that are physical shock and heat - guess what's inside an engine a lot of the time?
These magnets inside our bikes are of the generation prior to the super PMs we have now, and definitely have a finite life. How long that is, I cannot say, but it's not forever.
Having said that, my oldest PM rotor is 40 years old and while I'm sure it's not as strong as it was, it's still knocking out the magnetic field quite well.
Perhaps it wouldn't be doing too well if it were still under the same loads as it used to be, but it's generating useful output.

[Robbiem1961]

I've fitted an additional earth wire from the r/r direct to the battery, a brand new stator was fitted, and tested out by a professional electrician at work, the charging circuit is as per the factory, there is no obvious damage to any of the charging circuit, and the continuity between connecting wires is good; the r/r was purchased via the internet and selected by model (gx i think, though I'll need to check to be 100%) and year 1985:
a new rotor is (from memory) £350, while gs 500 parts are readily available and much less expensive, I'm sure that suzuki would allocate a 1985 gs 850 different part numbers to a 2005 gs 500, though i may be wrong, i often am
The gx model designation was determined by uk suzuki importers Robinsons Foundry Ltd after i telephoned them and explained that neither my frame or engine
numbers had enough digits to determine which model:
She's a later model, no kick start and cv carbs, so an eighteen pole set up within the altenator cover, i have tried to count how many times a screwdriver is both repelled and attracted, but establisbing where the fields start and stop is nigh on impossible:
i have to admit that i may be getting a tad shirty with this little issue, because i keep taking my old harley sporster out!!!!

[wymple]

These are a pretty simple setup, actually. 3 stator wires direct to the R/R, a hot & a ground off the R/R. That's it. When mine refused to work with all new parts, it turned out that the hot wire from the R/R had to go straight to the battery, and all was well. I hooked it up to the battery post on the solenoid, as that was convenient. I don't know how the voltage was getting lost, nothing got even warm.

[Robbiem1961]

One stator phase is routed up through the right hand handlebar switch and then returns to the reg/rec, the red wire off of the reg/rec goes directly to the battery, the remaining black wire was earthed to the frame, i added an additional loop of wiring and connected it to the negative pole of the battery, happy days? It should all be working, but it's not

[wymple]

That odd loop on the stator is a no-no these days. Most, including me, run it straight to the R/R with the other 2. After that I don't know what to tell you if the rest is new.