CB125K3 by RGP750

[RGP750]

Rats!! missed that
As Ash says all k3/4 and 175's had it,
Took mine off last night and it had been cut not broken ,Weird!
No great hurry one will turn up .
Cheers

[RGP750]

Oh Dear looks worse than I hoped .
At the mo thinking the crank may be toast as well [ Guests cannot view attachments ] [ Guests cannot view attachments ]
Anyone got a clutch? [ Guests cannot view attachments ]

[RGP750]

Well Wish me luck with this one.
Been apart before, lots of lovely red hermatite everywhere.
Looks like it has been filled with sawdust??? no idea what it all is .
No sign of any recent oil either.
When the PO put it together he wouldn't have got first gear as one of the gears was on the shaft backwards so no chance of the dogs engaging.
Managed to shift the stuck piston with a few days soaking with WD and some heat and a large hammer and 40mm ally bar, didn't take that much effort.

[Rozabikes Tim]

Thats a challenge mate. Right up you street I'm sure

[RGP750]

Yes the thoughts of getting this wreck looking good again is what keeps me going

[AshimotoK0]

Oh dear Rich ...I was toying with the idea of taking on that bike in a wild moment , as they are lovely looking little bikes ...kind of glad I didn't now. No worries though, you got the holy grail parts for it i.e exhausts and engine bits are bound to be out there somewhere.

If  I can be of any help sourcing parts in Japan  then just shout and I will ask Chris  but shipping is going to be expensive...maybe France is your best bet ...I had to do the same for my CD125A sloper.

The only engine I can find in Japan currently is for a K1 but they are even rarer than the K3 so they have to be out there for the later model.

https://page.auctions.yahoo.co.jp/jp/auction/c671332893

[RGP750]

Thanks Ash
Bet you are pleased you didn't take it.
Really didn't expect to find this inside looking at the outside.
I have another crank coming this week.
Getting the cam ground and the head re bushed.
Andrew on here with the K3 says some of the 175 gearbox parts are interchangable and i have a
175 box here so will check that.
Pistons, clutch plates ,cam chain adjuster wheels etc are available from CSML or DS
Be great to resarect this engine.

[AshimotoK0]

Thanks Ash
Bet you are pleased you didn't take it.
Really didn't expect to find this inside looking at the outside.
I have another crank coming this week.
Getting the cam ground and the head re bushed.
Andrew on here with the K3 says some of the 175 gearbox parts are interchangable and i have a
175 box here so will check that.
Pistons, clutch plates ,cam chain adjuster wheels etc are available from CSML or DS
Be great to resarect this engine.

Sounds like you have a plan then. Where did you find a crank so quickly  Rich?

Look at this CB160 engine my friend took apart recently !

[ Guests cannot view attachments ]

[RGP750]

May be worse than mine Gulpl!!
just bought a really nice looking clutch complete. oil spinner complete and gearchange shaft for £50 then
he gave me 20 euros back for postage RESULT!!

[Menno]

Maybe a solution?

https://www.ebay.de/itm/Honda-CB-125-K3-Motor-komplett/152795006482?hash=item23934ac612:g:yewAAOSwR2RaEo9Y:rk:41:pf:0

[RGP750]

Thanks Menno ,only just seen your reply.
Mine has cleaned up very well actually.
Amazing what can happen when someone carries out a "re build"
Take a look at the ill fitting head gasket, no wonder there was no oil in it,,helped to oil the outside of the engine. the gasket doesn't cover the oil return hole from the top end.

 In it's past life looks like a piston has blown up, bit of work to do cleaning up the comb [ Guests cannot view attachments ] [ Guests cannot view attachments ] [ Guests cannot view attachments ] ustion chamber.

[RGP750]

Sent the cam away middle of last week to David Newman Cams in Orpington Kent.
What a great company 4 lobes re-profiled and main journal skimmed .
Now just to get the head re bushed to suit the cam .
This bike had been severely bodged in it's history,loads of red Hermatite everywhere .
Take look what is appearing out of the oil hole that had the most wear.
Cam back in less than a week and £60 all in Result

[Laverda Dave]

Looking good Rich. Newman Cams are very good. Mike Newman is always happy to chat on the phone as well.

[Trigger]

You have to work out how to make a bush that will not spin in the housing 

[Laverda Dave]

You could try Russell at J D Autoworx in Wallington, Surrey who may be able to make a bush with a suitable peg arrangement. Last time I visited he was developing a bushing arrangement for SOHC engines.