Honda cbr 250 and 125 engine swap?

[Jay46]

Does anyone know if it is possible put a Honda cbr 250r motor into a cbr 125r?

Thanks

[RhynoCZ]

Question: why?

EDIT: I just think it's cheaper to get a CBR250 rather than swapping the engine and yes it is possible, people put various of single cylinder engines from endurous into 125cc frames for many years.
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'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
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[BikerMatt]

Don't go off topic, just answer the guys question jheeze
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[stevo as b4]

I don't know, it would depend on engine dimensions, mounting points and clearance for various ancillaries etc. You would have to look at a CBR250 and CBR125 together and probably take measurments.

I would guess that dimensionally the CBR250 is very different to the CBR125, and that the two motors are completely different designs.

I would also think that if you were wanting to do an engine swap into a CBR125 that the best option and the most directly related motor would be the CBR150 engine, which I believe is around 20bhp and apart from the 4valve head there are close similarities in design to the CBR125 unit.

[Vincent]

Anything is possible, it's a question of how easy/hard it is. In this case, I'd suspect quite hard. One of the first things to check is wether or not you can get the sprockets to line up. One way to find out is to buy an old 125 frame, you can pick damaged frames up for very little and see what happens when you try to stick a 250 engine in it.

You probably should be asking - "has anyone ever seen a CBR125 with a 250 engine in? The best hybrid projects are those that have been done already - all the info is there.
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Space Is Deep

[Blau Zedong]

[watafu]

No you cannot fit a cbr250 engine into the 125 frame unless you are intending to replace every aspect of fueling, electrics, brakes and are particularly good at welding to make new engine brackets. All in all its cheaper to get a bigger bike like a honda hornet or something along those lines.
The biggest engine you can put in the stock frame that will drop in is the cbr150 engine, then buy a big bore kit up to 200cc+, replace your carb, stock ecu ect ect depending on whether its the newer 150 injected engine or the older carbed model like I have.
Now once you have all your parts, if your trying to drop the engine straight in, you are going to find a looooot of differences, the cooling system is slightly different, at the moment I am having to figure out how to make it all work properly (not sure if the carb needs coolant running through it??) and also you will have to buy some additional parts to make the exhaust fit.

All in all its going to cost you an arm and a leg and a lot of time.

[N cee thirty]

yes, fits straight in, no issues.
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[pits]

[Timmeh]

[dangerousdave]

[prawny1]

would be much easier to fit the cbr clone 150 or 200cc engines
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hellkat wrote:

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[Carvel]

Just buy a fireblade you fat fuck.
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2002 Aprilia RSV1000R, Cbr600Fs, Mk1 B12, Vfr400 NC30...

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[Kai.Wilson]

Im guessing your only on a cbt

you may aswell buy a cbr250 and put a cbr 125 plate on it, would be much easier

[SQL]

[Teflon-Mike]

CBR250 'single' makes 26bhp.
CBR250R 'four' makes 40ish.
The 250 single motor would be a lot of hassle and effort for not a lot of gain.
The 250 'four; would be a fucking nightmare, and a waste of a classic.

CBR125 is a useful four-stroke, 'sports style' learner-commuter. Its not meant to be fast.

CBR250 single is a moderately useful, 'sports-style' four stroke A2 complient commuter. Its not really very fast either.

If you have a licence to ride a 125 modded beyond Learner/A1 licence restrictions... just get a bigger bike.

If you don't have a licence to ride anything beyond Learner/A1 licence restrictions... fuckit.. just get a bigger bike... might as well be hung for a sheep as a lamb, and you'd probably actually be breaking fewer laws.
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