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Discussion Starter · #1 ·
I have a CB 125 k5 (France) and am wondering how to remove the valves and springs. Unlike many CB models cylinder top on this model is one piece, so like in the photo, the rocker arms are above the springs. So does anyone know how I can remove the springs and valves? It seems like the springs will be blocked by the rocker arms. Can't find a guide anywhere.
I believe the American model cb175 k5 is similar to this one and maybe the CB 125s (but this one is of course 2 cyl.)

Trying to remove the valves to unstick them and clean them, as they are probably the reason why my engine won't start. Has been standing still for 10 years and the valves of the left cylinder are stuck..

Any help would be appreciated!
 

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Just looking at the schematics on the CMNSL site, the CB125 head is quite different to the CB175.

https://www.cmsnl.com/honda-cb125k5-france_model15847/partslist/

Right hand side cam bearing appears to be part of the head casting.

EDIT On second look, there IS a removeable bush bearing the tacho drive, part 3 in the spark advancer schematic.

On the left side, removeable bush is part of the advance retard mounting plate, cam chain being on that side of the engine.

Looks as though that plate has to be removed, then cam will come out through left side of cylinder head, maybe after removing cam sprocket bolts.

But that's all just my speculation, no substitute for work shop manual.
 

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Cant seem to be able to zoom into your pictures, are the inlet rockers missing ??

Valve stuck open ( exhaust ) by chance ? and now maybe bent ?

You know now of cmsnl which can only help you.
 

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Dam computers........top picture zoom in shows inlet valves missing, but bottom picture shows inlet and exhaust valve present, some thing odd.......?
 

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Dam computers........top picture zoom in shows inlet valves missing, but bottom picture shows inlet and exhaust valve present, some thing odd.......?
Pictures from cmsln are based on part list avalaible in documentation.

I have given engine to the workshop last winter, so if You will be in trouble just ask. I have made some photos before parts where ordered.

https://photos.app.goo.gl/xCfz9EDvd79yLzr62
https://photos.app.goo.gl/7HHQjFtwpxLQDi9b2
https://photos.app.goo.gl/AEqzaJLIlUGzVchh1
 

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Discussion Starter · #8 ·
Okay, I removed the rpm counter cover, then the cam with arms slided right out so I could remove the valves.
Any tips on if I should lap the valve seats?
 

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Discussion Starter · #9 ·
Dam computers........top picture zoom in shows inlet valves missing, but bottom picture shows inlet and exhaust valve present, some thing odd.......?
Pictures from cmsln are based on part list avalaible in documentation.

I have given engine to the workshop last winter, so if You will be in trouble just ask. I have made some photos before parts where ordered.

https://photos.app.goo.gl/xCfz9EDvd79yLzr62
https://photos.app.goo.gl/7HHQjFtwpxLQDi9b2
https://photos.app.goo.gl/AEqzaJLIlUGzVchh1

That's great, care to share more pictures? Did you restore the whole bike, is your story somewhere?
Thanks
 

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I haven't restored it. It was in operation, when I have bought it. I like some patina on engine.
The engine overhaul was done by local workshop during winter (so mechanic was not overloaded by current orders from modern bikes).

Full album is here:
https://goo.gl/photos/WLGhSqTDfzeeDZid9
but story is only in my notes.
 

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dionvh, PM me your email address. I have found a CB125 Factory Service Manual written in French I can send to you.
 
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