cb125 performance mods. Got any?

Powroll used to sell some great hop-up parts, but they're all but non-existent these days. Their website is still up, albeit barebones. Maybe shoot them an email and see if they're still offering parts and service?

You can also bore the case to accept a CB750 sleeve and piston, which I believe would take you up to 145cc. Add a cam and some headwork and you should be well on your way.
 
I believe it is the XR200. There's a thread out there somewhere with TONS of good hop-up info in it, as well as mix and match combos/compatability. I'll see if I can find it and report back.
 
Here are a couple of good links, the second is the one I was referring to above...

http://planetminis.com/forums/vintage-honda-xr75-jdm-vertical-motors/152161-cb100-mods-where-look.html

http://www.thumpertalk.com/topic/404455-hotrodding-an-sl100/
 
Seek out the "oldrice" forum.
They have PDFs of a bunch of old speed tricks.

Really kinda a waste unless actually racing the thing though as a fast cb125 is still the slowest thing on the road
 
A lot of truth in that statement ^

There are a few larger motors that essentially bolt right into the 125 frame, they're discussed in the links above. May be a better way to go rather than polishing a turd
 
Those bolt in motors might be larger, but really don't "feel" any faster.

Play to a bikes strengths. Speed ain't one of the 100/125 strengths.
 
I own a GS550, CB350, DRZ400s and now a mint CB125. It is not about speed with this little guy, I just can't leave anything stock. Lol
 
Changing things just to do it is silly.
Have a purpose.

If it is mint then enjoy it for what it is.Or move it on and find another small bike that might be able to go fast.
 
If you want to go fast, sell it now and get a YAMAHA 2-stroke. Unless you really have a passion for this, you might not get what you want.

I like small four strokes. They're stupid and no matter what you do to "sup" them up, they get even more ridiculous. I grin every time I see a post from Texasstar because their bikes (father and son) are completely ridiculous and the coolest things on the block.

So what is your goal? Also, are we talking a twin or single? Would you be willing to form a full fairing or duct work for ram induction? You might not gain any significant performance, but exercising the concepts could be worth it if you're into that kind of thing :)

How crazy do you want to get?
 
We are currently swapping a XR200 engine into a Cb125. It's basically a bolt on with a little trimming of the rear engine mount bracket.
 
I know that a lot of the vertical lifan motors will bolt in. I had a cb125 cafe project that I bolted in a lifan 150 with no issues.


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Pods are a downgrade as far as performance goes.
Also these small singles hate short exhausts.

they are making about 100hp/L
Not exactly choked...,,,
 
You have a bike that costs pennies for parts and just about define bullet proof.

Find out what it can and can't do. Put whatever you want on it until you find what you like. Pod, velocity stack, a length-tuned intake tract, leaf-blower supercharger, Ninja front end, cut valve seats and lower the deck, try to modify an existing electronic ignition or pull the magneto off of a mower and throw it on, make it a mono shock rear, change sprockets and see what it takes to break a chain, make a fiberglass seat, fit an XR tank, increase clearance and travel, find out what components from other bikes will or won't fit, this series of motor spans two decades, make an electric-start AT engine fit...

What you have is a cheap expendable toy. If you want to learn about bikes, there's your subject. If it blows up, how much damage do you really think could be done? Sounds like a lesson learned if nothing else.

These bikes show up DAILY on CL for $100-200 complete. Just this year I bought a non-runner in that range.

Post pics, let forum vote.
 
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