Author Topic: CB125K3 - Future Project  (Read 6647 times)

Offline Toko_Jo

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Re: CB125K3 - Future Project
« Reply #15 on: July 02, 2025, 09:51:54 PM »
What docs. do you have with it if any? Bit of a problem if you have nothing and it's an import.

Offline Craizeehair

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Re: CB125K3 - Future Project
« Reply #16 on: July 03, 2025, 11:29:35 AM »
Currently working on that with the PO

Offline Craizeehair

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CB125K3 - Future Project
« Reply #17 on: November 09, 2025, 09:54:42 PM »
I found myself with some time to kill this weekend and as the CB350 frame is still away waiting to get some welding done, I decided to see what was what with this little CB125.

I sorted through the assorted tubs and boxes of bits and managed to gather up all the carb parts and reassembled them and fit to the bike. The throttle cable hadn’t been fitted properly and wouldn’t move so that came apart and put back correctly. Popped a battery on, checked compression, checked for spark, all good there, which surprised me. Hooked up the remote fuel tank and connected to the carbs, a quick tap on the bowls stopped the right hand side overflowing.

I’m not sure if it it’s necessary but there is no electric start on this, so I gave it a few prime kicks before turning the key on and I kid you not, it coughed on the first kick and fired into life on the second, the old gentleman I bought it from said it had been sitting for many years as it was one of his late fathers projects that had never been got round to, so I really wasn’t expecting it to spring into life quite so easily, I was massively surprised and impressed.

I do have a couple of questions though if anyone could help?

The exhausts seem to be one piece, there are no clamps joining the silencers to the down pipes, the left hand one is solid and one piece, the right hand one, separates and pulls apart and is leaking at that join (circled in red below)when running, is there a way to join / reseal this connection?


Also, the coil is producing spark at both plugs but the right hand lead does have play in and out of the coil if pulled , I was convinced it wouldn’t work as there is so much free play in and out of the coil… for want of a better phrase. I was thinking I could maybe epoxy around the lead where it enters the coil to stop the movement and preventing any issues down the line, I’m not sure if that makes sense reading it back but I don’t know how else to explain it!

I have a feeling that if I decide to keep it and finish the job, finding all the bits I might need could be a bit of a job.

Offline TrickyMicky

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Re: CB125K3 - Future Project
« Reply #18 on: November 09, 2025, 10:34:00 PM »
Have just zoomed in on photo, KMH speedo and a yellow headlamp bulb definitely point to French origin. Have fun.

Offline Craizeehair

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Re: CB125K3 - Future Project
« Reply #19 on: November 09, 2025, 10:36:40 PM »
Thanks.

Yep definitely French, the VIN plate on the rear of the frame is in French, I didn’t notice that when I first got the bike.

Offline TrickyMicky

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Re: CB125K3 - Future Project
« Reply #20 on: November 09, 2025, 10:44:29 PM »
Looking ahead, (a few weeks???) to when you are ready to kick it into life, do not be tempted to re-position the kick start into a more vertical position. If they are in any way similar to the old CD175, people used to do this, and on a good full swing right to the bottom the mechanism used to punch a hole in thetop casing.

Offline Craizeehair

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Re: CB125K3 - Future Project
« Reply #21 on: November 09, 2025, 11:21:20 PM »
Ah ok, that’s interesting as I had previously looked at a CD175 tha had a crack in the top casing that I couldn’t work out, that now makes sense.

Offline Johnwebley

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Re: CB125K3 - Future Project
« Reply #22 on: November 23, 2025, 07:59:42 PM »
An early forerunner of the 175 and 200,

If you decide to get a new coil, ensure it has a low ohm primary circuit,
I think close to 3,

I had a coil with a higher resistance, and it wouldn't spark above 7k

Took me ages to find out the issue

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lifelong motorcycle rider,and fan

Offline AshimotoK0

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Re: CB125K3 - Future Project
« Reply #23 on: November 24, 2025, 07:38:17 AM »
You need to speak with Richard on here member RGP750 .. he has almost finished restoring a rare UK one ...  very few genuine UK CB125K3's sold in the UK....  Not sure why as brilliant little bikes.

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