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Discussion Starter · #1 ·
Hi, I'm looking for a little help with an 1986 XL125r which has no spark.
The bike was running fine, easy to start, etc, but just stopped as if the ignition was switched off while miles into the hills. Long walk home...
First thought was CDi, so bought one of the generic Chinese 6 pin CDi's from Ebay. I'd have bought something better, but real ones seem to be unobtainium ? and my 1985 Honda quad uses a similar (oh how I wish it was the same type) CDi after it's original one failed a few years ago, and it runs fine.
Still no spark.
Checked all the wiring, tested each wire with the ohm meter for continuity and checked each connector for the same. Repaired the alternator wires properly as someone had cut and spliced them badly in the past. Checked all the earth wires and connections. Checked the ignition switch was working and bypassed it with a straightened paperclip in the loom plug so I know it's 'on'. Unplugged the black/white tracer 'kill' wire from the ign and kill switches, so it should run but not switch off.
Still no spark.
Checked the stator coils for continuity and for the alternator internal earth. Spun the engine over with a drill on the flywheel nut and have 7ish volts from flywheel coil to the CDi. Thought this sounded a bit low, so sent the stator coil to Westcountry Windings who recon these things, but they tested it and say it's fine.
Swapped the ignition coil, plug cap, plug for new.
Still no spark.
Swapped the AC regulator and DC regulator/rectifier for used spares.
Still no spark.
Wondered if the original CDi had died, but perhaps the Chinese CDi was faulty ? Bought a different Chinese CDi and coil to try and eliminate this possibility.
Still no spark.
Clutching at straws, so fitted a new Honda pulse generator on the end of the cam.
You guessed it, still no spark...
Looked on line for the pinout of the generic Chinese CDi's and checked this against the Honda diagram and how the bike is actually wired, exactly the same.

I've got the manual with wiring diagram and have now worked my way through the wiring very carefully, testing every damn wire and connection several times, over a period of a few weeks. Swapped everything I can swap and swapped parts in rotation just in case I have two parts which are dead and just swapping one is only fixing half the fault.
I've got 7 volts at the CDi, from the flywheel.
A measurable pulse from the pulse generator to the CDi (Old school analogue meter)
Power at the coil spade terminals (coil unplugged) from the CDi when spinning the engine.
Every earth wire is earthed, tested.
Surely I should be getting a spark?
I must have missed something? or I'm doing something stupid? but what?

Thanks, Grunthos the Flatulent
 

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Discussion Starter · #4 ·
Hi ! Thanks for the replies.
The fuse and holder has been removed by a previous owner, so that's not the trouble unfortunately.
No dead man on the stand or clutch lever. The neutral light is just a light, rather than an inhibit switch and we have tried earthing it's wire, so the light is on all the time and the bike thinks it's in neutral, so would start if it was inhibited somehow.
My current plan for the weekend is to temporarily swap the quad bike CDi wiring to the same layout as the XL and see if it will run on the XL cdi's.
 

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If the CDI is the same as the NX650 your welcome to try this.
 

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Discussion Starter · #6 ·
Well, after much messing around, the problem is fixed. Turns out that West Country Windings were full of sh*t when they charged me for testing the stator and said it was fine. Sent it to Rex's Speed Shop who tested it and pronounced is faulty, they rewound it, I refitted it to the bike and it fired up :) Happy days....
 
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