1982 Suzuki gs 125 cdi issue

[type25dude]

Hi, I’m tackling a 1982 Suzuki gs 125, drum brake, kick start model. The previous owner has chopped at the wiring to install a non stock cdi, but seems not to have got it working so the bike has sat for a long time. The bike has 6 wires coming from the stator, in two groups of 3. One group has a red connector, the other group has a clear connector. The plugs where they would have connected to the cdi have been cut off, so I’ve no idea which order the wires would have entered the cdi. Also I believe the cdi 032900 00530 is the correct one for the bike, but has only 5 pins, where does the 6th wire go.

Would anyone have a photo of how the connectors enter the cdi showing the colours of the wires. Or could you describe them?
Also, what colour wires connect to the coil?
Also, where Is the vin number on the frame, can’t find it.
Thanks.

[WD Forte]

For a bike that old that's had its wiring hacked about
you should be the one showing pics.

It would be a simple enough bike to put right if most of us had
it in front of us, but vague descriptions don't inspire good guesses.

The harness coming out of the engine will have wires from the stator pulser and neutral switch with possibly a ground wire too
Maybe more if its an AC CDI bike that someone tried to mod
to a DC CDI .

Connector colours mean nothing, cable colours help more
but as we cant see it we cant really tell or even make a guess.
____________________
bikers smell of wee

[stinkwheel]

From a quick and dirty look at some sketchy wiring diagrams. Five wires from the stator on a GS/GN 125. Three are yellow and go to the reg/rec and two for the CDi pickup coil (green and blue).

The CDI has 5 wires and two connectors. With the 2-pin connector on the left, going left to right it's green from pickup coil. Blue from pickup coil. Then in the three pin connector it's orange and white to the ignition coil and kill switch, white to the ignition coil and black and white which is earth.

That seems to be a pretty universal setup for all the small 4t suzukis of that era.

https://i.imgur.com/6NrRC0j.jpeg

Some models have a gear indicator which would have six wires coming out of the engine in a bundle.

If no gear indicator, there may be a single wire for the neutral switch also coming from the engine. It's unhelpfully blue like one of the pulse coil wires. Fuck you Suzuki.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[WD Forte]

In their defense, I reckon the blue neutral wire is probably a strap on
and not bundled in the same sleeving as the stator and pulser cables.
There may be a protective outer sleeve as it leaves the case but
just whipping the sprocket cover off and observation would show this.

As for the spark unit, it has two seperate plugs.
One 2 way for the pulser input and one 3 way for power, ground and coil connections.
____________________
bikers smell of wee

[type25dude]

Hi, thanks for the replies, very much appreciated. sorry for the lack of pictures. I’m attaching a photo of the wiring. On the right you can see where the 6 wires branch into 2 groups. One from the red connector with a red, white and purple? Wire, the other from a clear connector, with a red, blue and a green? and white striped wire, though the stripe isn’t obvious in the photo. The last owner wired in a circuit board which lights up when the kickstart is pushed but has no other function I know of. I’ve no yellow wires, I’d expected 3 from the stator, so this may predate them.

[WD Forte]

I think it's safe to say
What you got there is a right old mess
as he couldn't get it running I would regard any work done by
the previous owner as dubious at best and probably shite

that circuit board you're obscuring looks like an aftermarket spark
unit but I cant see enough of it to tell if it's a TI or CDI type
The track connecting the coil terminal to one end of a poly cap
suggests its possibly a dump cap and thus a CDI sparker.


If I had it here I'd rip out the PO's crap work and start over.
Its a simple bike so putting it right will be easy enough
but the previous bodges will get in the way and are not to be trusted.

Start at the lh side and remove the sprocket cover
and examine and note the 6 cables that emerge from the engine.
There should be 3 yellow ones from the stator
A green one plus a blue one from the pulser and a single one from the neutral switch
One pic is a start but that's all
Take a lot of decent pictures and show us or its all a waste of time.
____________________
bikers smell of wee

[stinkwheel]

The bare twisted wires poked optimistically into the solder pads on that PCB tells you everything you need to know about the previous owners electrical engineering abilities. As above, regard anything he's touched as a total bodge job.

What you really need is a proper workshop manual which will have the correct wiring schematics for what you're supposed to have. I'd just spend the money on one. If you have the model and year, you'll be able toget a haynes or clymer manual.

If it was me, I'd strip back anything the previous owner has touched and start from there. Might even be worth getting a loom for it if he's been at it elsewhere.

The workshop manuals usually have infor on engine number ranges too. Your wire colours don't seem to match what I was expecting which makes me query if either the wires in your picture are original or if it has the engine it's supposed to have. Do the colours on the "bike" end of the connectors match the ones on the butchered side?
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[type25dude]

Hi, I’ve attached a few photos, though didn’t have a socket to take off the panel for the stator. 9 wires leave the stator area, breaking into 3 groups of 3. I don’t know if the Haynes manual covers this bike, it’s from 82 on. An original workshop manual would be good though. The wiring all looks original, it’s certainly old enough, I’ve already stripped off the shonky wiring from the PO, bar the white earth wire for the battery and the circuit board.
Thanks for taking the time to look over it all.

[stinkwheel]

A bit of detective work.

Picture of a confirmed OEM reg/rec for a 1982 GS125 shows the blue on white, red on white and yellow are your charging phases.

CMSNL lists the correct ignitor unit as part: 3290005300 or 3290005220 depending on varient. (I think the first is electric start, second is kick-start). Both are like rocking horse poo and very expensive in the unlikely event you find one.

You MIGHT be able to fit a later model or pattern/universal CDI but if you can't find a wiring diagram, you're going to need to trace those wires back and see what each one does so you know where to connect them. You'll also need a wiring diagram for the bike it's off to see where they go.

For what it's worth, they are to all intents and purposes the same engine as the much more common GN125 so if I was to be fitting a CDI off another model, that's what I'd go for.

Another option would be to fit a full used charging and ignition system (stator, rotor, CDI and pickup coils) off a different model suzuki. The main determinant of what will fit is the crank for the taper and keyway positioning. Depending on which varient you have, either an '85-88 DR125s or an 89-94 GN125 share the exact same crank.

To see what varient you have, you'll need the frame number which should be stamped on the headstock. Then you can check this chart:
https://images.cmsnl.com/img/partslists/suzuki-gs125-1982-z-general-export-united-kingdom-e01-e02catalog-preface_bigsue0308prefac_7b4b.gif
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[type25dude]

Thanks for your hard work on my behalf. Doing a quick check for the 3290005220 shows they are rare and expensive, more than the bike itself, but would be the easiest solution. I did buy the cdi for a gn/gs 125, which has 4 pins and a red wire, and still have the cdi used by the po, which is a 6 pin I think. There must be some way to wire up one of them. I’ll take a picture of the gn cdi tomorrow to see what you think, I guess the po was thinking the same thing when they did their hatchet job.

[WD Forte]

Suzuki original spares will be costly even if still available.
The good news is the chinese made loads of bikes cloned on this motor so I'd look there for much cheaper parts but first you have to establish what it is you have exactly.

I suspect you have the early AC CDI type ignition.
____________________
bikers smell of wee

[stinkwheel]

If the printed circuit board in your pictures is the CDI used by the previous owner, I'd be amazed if it ever worked.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[WD Forte]

yep, it wouldn't work as is

I reckonthat PCB is an AC CDI spark unit
AC in from source coil to ALT terminal
then to square 4 pin chip which is a bridge rectifier
Big 400v cap is the dump cap
IC top left is an SCR
All the bottom stuff is signal conditioning to handle the pulses in on HI and/or LO
and it advances retards the trigger signal by using the switches and componets
to fire at lower/higher thresholds.

KILL dumps source coil output to ground to snuff sparks
TAC tacho ouput
COIL well... coil obvs

Bin it, you can buy new CDI boxes for 10-15 quid and suitable connectors and cabling for a few quid
there are probably Suzuki cloned ones for similar prices.

That bike looks to be in a very shabby neglected state, all that wiring needs removing and and redoing properly
and the frame derusting and some paint thrown at it too.
____________________
bikers smell of wee

[type25dude]

Hi,I've added a picture of the cdi I have for the bike, though I don't know how it could e made to work. The frame code is given in the logbook as 103254, but with no preceding code, I can't find I on the headstock. I will b e gone for a couple of days so won't be able to reply till Tuesday. The bike is kept at work, as a project for a group of teenagers at my school. Painting and fresh loom would be nice but beyond what I wanted to do, though the tank and mudguard will be painted. I think the photos make it look a little worse than it is. I just wanted a bike to show them how to change oil, brakes etc, didn't count on any major difficulties. Bought it at short notice, cheap. I know, I know......

[stinkwheel]

[WD Forte]

[type25dude]

Ac cdi is ordered, a cheap one to practice on, the picture shows what the pins do, and lists the colours of wires going to it. The question now is which colour wire goes to which pin. Black and white seems to be kill switch. Red I assume is power. Don’t know where the rest go. Suzuki seem to have used various arrangements of wiring according to some of the sites I’ve read, whatever was within reach I think.
Apologies, of course the previous picture was the regulator, I hadn’t noticed the original set in behind the engine and a bit crusty looking, still, I have the replacement if the original doesn’t work.

Cheapest 032900530220 so far is £220, so a very distant lastresort.

[stinkwheel]

As above, a picture of a confirmed OEM reg/rec for a 1982 GS125 shows the blue on white, red on white and yellow are your charging phases.

So score those off your list. Chase the others through with a continuity tester of some sort.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[type25dude]

Will do, thanks. Much appreciated.

[type25dude]

I’m still working on this problem so thought I’d post an update.
Of the 6 wires going to the cdi, 2 of them are for the pulsar/trigger, 1 is earth, and the other 3 seem to be power from the stator. The wiring diagram for the d and z models show the cdi to have these 6 wires, another for the kill switch (my bike doesn’t appear to have a kill switch or the wire for one) and a separate wire leaving the cdi for the coil.
I now have a 6 pin cdi. Can this be made to work? The 3 power wires running from the stator are red, red/black, and white. Can I join 2 of them together, or leave one out. Leaving one out, then connecting the cdi coil pin to the coil produced no spark.
One suggestion above was to replace the stator with a more modern one. What would I need to replace it , the bike is a kick start only. Thanks for looking.

[type25dude]

Still going on this. I've tried connecting the wires to a cdi, the two pulse wires, earth, one wire direct from cdi to coil, and 2 of the 3 power wires. Unsurprisingly, no spark. One suggestion I've come across is to connect two of the power wires to a step up transformer, and blank off the 3rd wire. My question here then is what voltage is expected leaving the stator, and what should go into the cdi. In other words, if I put in a step up transformer between the stator and AC cdi what do I expect to see going in and coming out of it. I've seen conflicting posts saying 12 volts, 15 volts or 400 volts. I don't know anything about 3 phase so what could I expect my 2 wires to produce, and what does the voltage need to be for the cdi to work? Thanks.

[WD Forte]

Step up transformer eh
Hmmm
Why didn't Suzuki do that?
Fuck good practise and systematic problem solving
Making a simple job more complicated with ill thought out
half assed ideas is always a good thing
____________________
bikers smell of wee