GZ 125 no spark

[robg123]

I have a 03 k3 gz125 with no spark,had been sitting -the guy took a vid of it eing jumped and firing up then sold it on.i have painted it ,cleaned carbs ,changed ignition,and now going to start it found no spark..
i have hard wired the clutch and side stand switches,cleaned coil terminals.next check is the side stand switch relay i guess.. does the yellow black wire ground to stop the engine?

[robg123]

just got myself a spark tester and have noticed with ignition on ,and me flicking kill switch on/off the sparkplug tester flashes when kill switch set to 'run' but no spark when i turn it over..

[alantf]

First of all try spraying the kill switch with aerosol contact cleaner. Second...you say that the previous owner got it to fire when he jumped it. If it started with another battery, I can only suppose your battery has a problem. Have you tested it? If not, charge it for 5 or 10 hours at 0.75amps (certainly no more than 2amps), disconnect the charger, leave the battery sitting for half an hour, then test the battery voltage with a meter, and let us know the results. Bad battery is one of the most common faults of the GZ.

[wacio]

Test components from the easiest to test ending with ignition module. Verify if your run switch is in run position than:
1. Fuse
2. Battery
3. Safety switches (clutch, stand, ignition switch)
3. Spark plug - try another one to see if yours is dead.
4. spark plug wire and coil - resistance - primary 3-5 ohm, secondary 17k-28k ohm
inspect spark plug wire for damage (could be melted if too close to head)
5. Pickup coil (crankshaft) - Resistance 400-650 ohm and voltage more than 5V (while cranking)
6. Ignitor - measure using multimeter per manual (I have one for GZ250 - not sure if your use same module)
Be patient - you'll get there

[robg123]

ok great stuff guys ill get the multimeter out.i have fitted new battery ,ignition key has been changed but i also have a spare plug with the wires chopper and twisted (as per haynes diagram so i know all is good .the kill switch also is on the starter circuit so i dont think its that as it spins over in on and doesnt when switch is off,i do have power at both coil wires when ignition is on.will try test coil and igniter today

[robg123]

coil 5.2ohm and 23k so seems within spec i guess

[robg123]

so i have hard wired clutch,neutral,sidestand switches to guarantee continuity,
side stand relay checked out ok ,
coil seemed within tolerances - the coil wires couldnt be the wrong way round could they?
checked r/h switchgear ,stop switch/started all working as they should.
it has brand new battery showing good charge.
tried different spark plugs
My haynes book only shows the ignitor test with a different model (gs125) where the pickup wires are on a seperate plug to the rest of the wires so can be unplugged and check for spark.. could i do the test with the cdi box plugged in and just probe wires?
getting frustrating.haha

[robg123]

https://1drv.ms/i/s!ApmwTPXyzTtBnwQdp_sYoN1rQenC wiring diagram

[wacio]

On your diagram the pickup coil is shown as part of the alternator - connected to the ground (black/white wire) and blue wire going to igniter. There should be connector (shown on diagram - two conductors) somewhere close to engine - probably under the tank. You can disconnect and check resistance there (between blue and black/white on cable going to engine) .

[robg123]

with the multimeter set to 2000 i was getting 245 ohm ..

[robg123]

It had a smashed ignition lock which i replaced - the replacement kept blowing fuses when ignition was on so was wired wrong for the bike - i have cut the wires and have hard wired the 3 sets of 2 wires as per the manual for the on position.everything lights up now.i just unplugg for ignition off until i get this spark problem sorted.

[wacio]

I have 400 ohm minimum in my GZ250 manual. I'm not sure if this applies to yours. After disconnecting check resistance coil connections to ground (engine or frame) to see if not leaking (should be infinity). Might be worth to check voltage on this coil while cranking. If you are getting close to 5V -I'd say part is OK. But if substantially lower or 0V - NFG.

Check and double check your connections - from what you're describing above you did major surgery to your electrics. It is easy to disconnect, short or cut something by mistake. Your ignitor should be getting 12V on orange/yellow from ignition switch - check that to eliminate messed up ignition switch possibility.

Check if its getting good ground on black/white going to ignitor.

Check all the other connections from ignitor by measuring cable resistance from ignitor harness plug to wherever they go on schematic. They should be all max couple ohm. For example meter stick probe into igniter connector to black yellow wire and check if there is continuity at the ignition coil (same color wire).

[robg123]

just checked for voltage and got zip..0.. can this be down to a broken wireor something?, or is seeing that the resistance is within range (apparently 150-300ohm) the pickup is bust

[robg123]

could be my cheap digital multimeter? orange yellow is wired to ground (on temporary plug) and there is power at the module on orange/yellow and black/yellow.

[robg123]

continuity between pulse coil plug/ignitor module, module to coils

[robg123]

also just started looking at my next problem with the ignition switch..so from the bike i have 6 wires ,on position i want R & O ,O/Y & B/W, Gr & Br. trouble is after testing the key ,i only have 2 sets of wires with continuity when key is 'on' .with the other two having continuity in the 'off' position.
Could i keep BW/OY seperate on one set and join the rest?or maybe crossing those two circuits might not be wise..

[robg123]

ignition sorted.red orange to key, the other is hard wired and only gets current when red/orange are switched on.

[wacio]

Great to hear that. Did you get the bike started OK?

[robg123]

no.haha.still no spark ..took stator off last night and had a look.seems to be some scuffing on the pickup,i dissasembled and cleaned it up then refitted,still nothing.
I think i may just bite the bullet and find another stator/pickup coil and ignitor box.i have a new coil on the way too.surely if they are all good it can only be a wire problem.

[robg123]

after further thought i think the problem is the anti theft resistor apparently fitted to some suzukis. Some have a 100 ohm .5w resistor in the ignition which give ground or power signal to the ecu, this stops people hot wiring the ignition as it misses out the resistor and the ecu will not trigger thecoil...well...i hope this is the case as i am out of ideas, tried another stator/pulse coil and also another ecu box and had no luck

[robg123]

ok new ignition arrived today and bobs your uncle spark straight away..bottom line dont buy ebay ignitions to later model bikes, it reminds me i had a yamaha ybr with exactly the same problem that i changed ignition on- its likely that the replacement ignition didnt have the resistor and i never could work out why no spark..ended up selling as a spare repair and the guy that bought had endless trouble too..living and learning