fitting a 250cc engine in a cg125

[simon_1561]

hi guys im a newby on hear and after a bit of advice.
i own a honda cg125 on a 1993.
i also own a superdream 250 i was wondering would the engine out the superdream fit in my cg.
im a mechanic by trade soo am mechanicly minded.
any help would be great

[skatefreak]

Not being a mechanic but somewhat mechanically minded there are a couple of basic concerns:

- How well would the bike carry the weight (frame/suspension), would it need modifying?
- Would the breaks be capable of handling with the extra speed/breaking load?
- Will the larger engine fit in the space in the CG frame and can you physically get it in?
- How much work would it be to fit the larger engine in there (plates to align bolt paterns etc)?

As you have both bikes maybe look at the manuals if u have them (CG workshop manual is bound to be online), look at the diagrams and compare the bolt patters.

I am sure others will have a better idea of weather attention to the rest of the bike would be required.

Best regards

-Jvr

[Alexio]

Honda already do a 250cc version of the CG, it's called the CBF250

Ok, I'm only joking. One of my biggest concerns though is that you're trying to fit a parallel twin engine in to the spare of a single? Even if you sort out the logistics of where the exhausts are going to go I don't think you'll have space for it to fit. I can't imagine a much larger engine going in to my CG, except if it's more bulky outwards to it's sides.

From the look of the engine size on Google images, I'd say it's far too big!
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will never give up his CG. I look at my fuel gauge more as a progress bar than a fuel gauge.
G: With my GSXR I do often effectively use it as a scooter with a clutch in town.
ms51ves3: why does it need 500 miles? Are you teaching it how to be a piston?

[binge]

Anything is possible...

https://i902.photobucket.com/albums/ac227/pitbikeben/Photo1176.jpg

[Frost]

The major issues i foresee are; mounting it to the frame will require a potentially complex design of plates, welded mountings. The engines won't be the same width, but the front sprocket must still line up meaning that the engine may need mounting over to 1 side to allow this.

[MarJay]

Well,

Read my sig. Bikes aren't like lego you can't just mix and match parts. Of course, with enough time, money, effort, blood, sweat and tears you could make it happen, but you'll end up with a worse bike than you started with.

There is also the question of value, your bike will become virtually worthless because the only real value in a CG125 is the fact that it is learner legal.

Not to mention the fact that the only conceivable reason for doing this is to somehow try to get around the learner laws and insurance...

Don't do it, its a waste of time. Do your test (if you haven't already) and ride the Superdream as it is.
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British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[The Shaggy D.A.]

Or sell them both and get a CB250RS.
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Chances are quite high you are not in my Monkeysphere, and I don't care about you. Don't take it personally.
Currently : Royal Enfield 350 Meteor
Previously : CB100N > CB250RS > XJ900F > GT550 > GPZ750R/1000RX > AJS M16 > R100RT > Bullet 500 > CB500 > LS650P > Bullet Electra X & YBR125 > Bullet 350 "Superstar" & YBR125 Custom > Royal Enfield Classic 500 Despatch Limited Edition (28 of 200) & CB Two-Fifty Nighthawk > ER5

[The Artist]

If you are mechanically minded then yes it is possible but it may not slot right in. You may need some modifications of brackets etc + wiring everything up.

[simon_1561]

thanks all the above have been noted looks like its a trip too my exs too get the superdream out the garage this is going too get messy

[c-m]

I'm curious as to why?

I quite like the suerdream

[Frost]

After riding one for a year, i don't! Every corner feels like imminent death.

[neatbik]

Its possible, but it will be a lot of work. I'm currently looking at possibly fitting a bigger motor in a CG frame, but its quite tight in there - let us know how you get on..

[pepperami]

i dont know if it`s true? but i believe that an XL185 engine will fit into the space????
just a suggestion !! what about an old honda rs250 lump???

i myself am looking into getting the CG150 top end, barrel, piston,carb, ect.
when i finally get mine (it`s in transit) , it`s an old 1981 model.

so i will need to know if the replacement parts you can get on Flea-bay will match my engine???
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I am the sum total of my own existence, what went before makes me who I am now!

[Smiley]

to pepperami
it does fit some models. but you need to take care before ordering, and check the crank mouth to fit the sleave into! otherwise you can bore it out abit! but im not sure how far you can push it??

[P.addy]

[Teflon-Mike]

[unitynotsocri...]

even if it did fir ,and it won't then you' d have to completly redo the swing arm and rear wheels,then months and a thousand pound later you'd end up wobbling into the hard shoulder when you get past 50mph.If you swap for a cb 125 ohc,or a 185 xl lump then you'd have to redo the electrics and switchgear completly.
Look out for the 200cc chinese pushrod engines,but fitting in the frame may show that the swing arm,rear sprocket alignment is out ,so not really worth doing.Dont be tempted by ANY chinese big bore kit as the barrel n head are differnt from standardised Honda cg's,the most you could bore it up is 150cc without draconian engineering work.
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nearly a normal tax paying tosser.......with ferrileness suzi100,cg125,cb125scb100n,cb175,cd100,cj250t,kh250,c15,125 bantam,super 6,rickman gs750,xt500,250rs,dt175,lifan125,dolomite1850,metro,Morris220ld,morrisfg,leyland princess,range rover,corsa,vw camper .now struggling with legs. MORE ORDER = MORE CHAOS