Honda xr 125L

[daverfrancis]

hi just joined this forum. I have a Honda xr 125l I was wondering what other engines fit I'd like to put a 250cc in if possible. It's a 2005 shape. Cheers
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D Francis

[P.]

Sell it and buy a 250... cheaper and better.

[Shaft]

[Teflon-Mike]

It's the Push-rod OHV CG engine... most of the CG series and CG-copy engines will fit....
As to alternatives? Well, most small displacement 'upright' single cylinder 4-stroke honda's share a common mounting pattern.. OTOMH, oooh! CB125J, CB100N, XL100, XL125, CB125S, SL125 city-fly, and probably a few more. These are all the OHC, over-head-cam 4T singles, and they do make a tad more power.. but it IS only a tad.. talking 1bhp!
Biggest, and the one you probably most want, would be the XL185 engine. The XL / CB250 single uses larger non interchangeable crank-cases, so that's about as big as you can stuff in that chassis without getting into metal-fabrication to chop and weld new mountings to your frame... but that is only teh start of the 'problems'...
As said, most of them motors and maybe a few more ought to litterally swap straight into your frame and bolt up on the mounting points it has where the CG lump does... at least at the bottom and front... they often have different top-plates, so you might have a little met-fab to do to bolt the cylinder head to the top tube... but THEN.. exhaust probably wont be big enough / line up... whether you use one designed for your frame or one for your engine.. so that would demand a 'special' making by some-one. Likewise the carbs and air-box.. unlikely to line up, would need some solution.. and electrics... most of the motor's I've listed are 6v electrics and many have points... so you'd have to find a way to convert the engine to 12v electrics or convert the frame to 6v... probably mean rewiring the whole thing, and swapping out an awful lot of components... OH! we also have teh small matter of aligning teh sprockets.. different bikes have different width back wheels, so the gearbox output shafts are different lengths to suit where the chain runs to clear the back tyre.... this may beg another engineering solution, extending the out-put shaft to fit the sprocket more out-board to line up with the one on the wheel, or shortening it, or spacing the wheel sprocket, or.. well.. ways to skin a cat....
All depends what engine you get, really... and that is another 'problem'.. what engine, and where to get it? Most desirable, I supposed would be that 6v XL185 OHC lump... rare little beastie... and most live in what are now reletively desirable 'classics'.... you'd probably be best looking for a whole XL185 (or other donor) to get your engine from, which would at least give you a fair chunk of the other 'stuff' you may need, like the ignition system and wiring loom and 'stuff'.. B-U-T... would of course make more sense just to ride the donor bike! Certainly a lot less effort... and if you are planning this to 'cheat' licence regs... not much less legal!

In short? Its a push-rod 125 4-stroke.. its NOT a fast bike, and never will be... even with a 185 or 250 engine in it, it will still be SLOW... IF you want a fast, Learner-Illegal dirt-bike... go buy a Yamaha DT125.... because you would be doing bludy well to get more than the 24bhp or so they can chuck out from ANY of the 100-250cc 4strokes, even if you percevered and solved all the more niggly problems around building a 'special' AND added a turbo!

Otherwise? Just enjoy the damn thing for what it is! A cheap, useful little learner-commuter, that is remarkeably capable, undemanding, and offers a heck of a lot of grins for your money, even if it isn't exactly the most eager machine on the road... b-u-t, still ought to be faster and more reliable than most (chinese) 4T-125's out there, so you are quids in... save your money to stick petrol in the thing and go places, save your spanners to do normal, propper maintenence and keeping woirking as good as it can.

Want a 'Project'? Go grab an unsuspecting CX500 or sommat, and do a Brat-Chop job on it for when you have a big-bike licence.
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My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[oscar777]

Im sure you can get a bigger bore kit for these? That would be the easiest way, then rejet carb.

Engine swap? Screw that, too much hassle.

If you actually have a license then the obvious option is to sell it (as they hold their value). And get a proper bike. Much easier.

If your on L plates don't bother throwing money at a 125. Get your license then get a big bike.
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Push bike with a 80cc jerry rigged 2 stroke---> CBR125R ---> GSXR600 ---> Ducati 1098SF

[oscar777]

Im sure you can get a bigger bore kit for these? That would be the easiest way, then rejet carb.

Engine swap? Screw that, too much hassle.

If you actually have a license then the obvious option is to sell it (as they hold their value). And get a proper bike. Much easier.

If your on L plates don't bother throwing money at a 125. Get your license then get a big bike.
____________________
Push bike with a 80cc jerry rigged 2 stroke---> CBR125R ---> GSXR600 ---> Ducati 1098SF

[moonzoomer]

New 200cc CG engine, 475 quid..... https://www.ebay.co.uk/itm/200cc-Engine-for-Chinese-CG200-GY200-Air-Cooled-OHV-163FML/311004742285?_trksid=p2047675.c100011.m1850&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20140107083358%26meid%3D7560126dc38e4a5c9ae6fd58940dd7a3%26pid%3D100011%26rk%3D1%26rkt%3D5%26sd%3D161277842649

[oscar777]

[moonzoomer]