I've got a 1981' Honda CB125S and I want a bit more displacement.I'm considering buying that kit on Ebay from the seller 'ophir4u' on the West coast who sells lots of China parts.He has this big-bore kit w/ 144cc w/ cyl., 61mm pist./rings/gaskets,etc. for $59 and it 'looks' pretty good.I'd like to really run my little CB All over the place and want to ask here if any one of you members have purchased/installed this pist./cyl. kit and what kind of wear you get out of it before having to replace it ??
144cc kit on Ebay for my 81' CB125..,anyone tried it yet? How's it working ?
- Thread starter grcamna5
- Start date
rupaulpierce
Been Around the Block
Curious about this too... However, I've read that the 200cc Lifan motor and xl185 motor will more or less bolt in. That makes more sense to me but full disclaimer, I have no idea what I'm talking about.
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rupaulpierce
Been Around the Block
Boring out the head, rebuilding the engine, and tuning it up is less complicated?
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I would leave my 81' 2-piece cyl. head as is, it already has better breathing ports than the early CB125 one-piece cylinder head and the company in OR. 'Powroll' recommended it would be ok if I just used the larger head gasket w/o having to change the diameter of the mating surface of the head and Terry Miller KNOWS his small Honda's ! 
;D
The top end of these engines come apart and go back together in a snap,No Sweat. I was just hoping to get some feedback from a person who already installed this kit just to see how they liked it over the long run. Do you have an idea you might install this kit on your later model CB125/XL125 rupaulpierce ?
;DThe top end of these engines come apart and go back together in a snap,No Sweat. I was just hoping to get some feedback from a person who already installed this kit just to see how they liked it over the long run. Do you have an idea you might install this kit on your later model CB125/XL125 rupaulpierce ?
rupaulpierce
Been Around the Block
Oops I meant bore out the cylinder... I see the kit comes ready to go. I have a 1 piece head so probably won't be going this route but following the thread to see what turns out!
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Nobody's bought and installed the ebay 144cc kit on their CB125S here on DTT? I'm a little surprised because so many of us here have the CB125's.. I really want to get it but just wondered if any of you have done it yet... I can be a 'test mule' for this kit if that's what it takes. :
i dont think you will gain enough power to make any difference.the engine is tuned cam design,valve and port sizes,carburetor airbox and pipe it is all tuned extremely precisly together,and one of them may not be able to breathe well enough to make the power gain.the first rule in any power gain on any good running engine is a higher volume of air needs to be able to flow through just increasing piston size does not gaurAntee a flow increase
I installed the kit and went up a few jet sizes and so far I Love the extra power;I also upgraded my bike w/ an oem Honda 1976 CB125J model stock exh. system which I think is more free-flowing than the 79'- 82' restrictive oem stock mufflers.
This big-bore kit is designed for the later CB/XL125 models w/ the 2-piece cyl. head.The crankcases on my 1981' CB125S(I think that 81' is the first year they did them this big;I believe the crankcases w/ the decompressor 'hump' in the back is an easy way to indentify which ones have the 70mm spigot hole) are already machined out to 70mm at the piston spigot from the factory but you can install one of these kits on pre-1981' engines if you have the piston spigot hole machined out to 70mm.The actual O.D. of the lower liner on this kit is 68mm.
I have plenty of flow w/ my stock 81' 2-piece cyl. head ports(I checked online and they did make a CB150 which was manufactured in Brazil and probably uses the same cylinder head)and airbox.
The kit comes already machined w/ nice tight clearances between cylinder and piston and is enjoyable to ride;even break-in is simple ! No issues & no problems.
I need to install stiffer clutch springs now and gear-up a bit on my final drive ratio because of the extra power. ;D
Do any of you know which model of Honda 4 stroke 125 came w/ the stiffest clutch springs ?
This big-bore kit is designed for the later CB/XL125 models w/ the 2-piece cyl. head.The crankcases on my 1981' CB125S(I think that 81' is the first year they did them this big;I believe the crankcases w/ the decompressor 'hump' in the back is an easy way to indentify which ones have the 70mm spigot hole) are already machined out to 70mm at the piston spigot from the factory but you can install one of these kits on pre-1981' engines if you have the piston spigot hole machined out to 70mm.The actual O.D. of the lower liner on this kit is 68mm.
I have plenty of flow w/ my stock 81' 2-piece cyl. head ports(I checked online and they did make a CB150 which was manufactured in Brazil and probably uses the same cylinder head)and airbox.
The kit comes already machined w/ nice tight clearances between cylinder and piston and is enjoyable to ride;even break-in is simple ! No issues & no problems.
I need to install stiffer clutch springs now and gear-up a bit on my final drive ratio because of the extra power. ;D
Do any of you know which model of Honda 4 stroke 125 came w/ the stiffest clutch springs ?