engine options (chinky content.....sorry)

[69chris]

hey guys,

im sure iv seen the answer to this already somewhere but cant seem to find it

the mrs wanted a 125 to whip around town on, wanted a bantam or sim but couldnt get on with the r/h gearchange,
so i found a chinky 125 and chopped it about a bit to try and make it look old'ish,

however, once it was mot'd and she had used it for a while shes decided it isnt fast enough for those 'out of town' runs,

so, is the another engine that will fit into it ?? dont mind a bit of cutting/welding/wiring etc, but something bigger that would bolt in would be better,
btw, its a cg125 based engine

cheers all

[stevo as b4]

I'm sure some of the 125cc Honda specialists on here might know more, but the CG and CB/XL/XLR engines are related and I believe they share mounting points.

I would say that there's a very good chance that a Honda XL200R or XL185 engine would fit without much work at all, if you could find one that is?

There are I believe various Chinese 150-160cc big bore top ends available for the OHV and OHC clone engines, but IMO they won't provide enough extra power to make it worthwhile stripping and re-building a motor with possible less than quality parts?

The XL200R lump is 18bhp. Probably of no use to you if your machine takes a Honda based clone engine, but there are 200cc versions of the Suzuki GS/DR125 engine and also the Yamaha SR/XT125 engine, that make similar power.

[CHR15]

a dayang dy200 engine will drop in.
____________________
Turbocharged drag thing / project death weapon / GK73A
Ste: I'm not entirely sure how you'd go about verbally abusing someone with a potato but I'm sure it's possible.

[69chris]

cheers guys, ill have an ebay search and see what comes up,
although it runs along ok with a farty old sounding exhaust note it just needs to run along a bit quicker
heres a couple of pics of it for anyone who might be interested, its rusting nicely now



https://i157.photobucket.com/albums/t78/71bugslug/v_zpsb31643e8.jpg

https://i157.photobucket.com/albums/t78/71bugslug/bikes014_zps0986fc03.jpg

[G]

Not sure I'd want that to go much quicker, looks like you've messed up the already poor handling.

She has a good life insurance policy in your name, yes?

[69chris]

[Rogerborg]

You might want to keep an eye out for the 233cc parallel twin from a Jinlun "250" or similar, coded as a 253FMM. They're also found in some in ATVs, but with reverse gears (could be lulzy). I'm not guaranteeing that it'll fit, just that it's a contender.

Proper job on the bike, but what's holding the rear end up?
____________________
Biking is 1/20th as dangerous as horse riding.
GONE: HN125-8, LF-250B, GPz 305, GPZ 500S, Burgman 400 // RIDING: F650GS (800 twin), Royal Enfield Bullet Electra 500 AVL, Ninja 250R because racebike

[G]

My (official) Honda CG always seemed fine at those speeds.
It generally maxed out around 65 and never bothered me holding it at that. Had 75 on the clocks with a gentle slope and probably a little tail wind.

So I'd consider a Honda engine, presuming that should slot straight in - but it will depend on what you mean by 'sound strained' - perhaps the issue is more deciding the sound isn't an issue? (Though appreciated the bike was obviously intended for form over function, so guessing that's going to include aural stimuli too.)

I've ridden bikes with overly stiff suspension and ridden hard tail push bikes and not too far off those speeds. I've also ridden bikes that handle well .

[69chris]

ta guys

i think its just all the lil chink engine has to give, she had a proper cg before she passed her test and iirc that was perfectly happy at 60 ish but this one sounds 'unhappy' beyond 50,

50 would be ok if it was a comfy cruising speed, its just a bit tiring when it sounds flat out

i appreciate my homemade exhaust prob isnt helping the situation but it was pretty crap before it was chopped up.............. usual gutless copy junk i guess

cheers again

[Rogerborg]

My CG-copy-engine saw a real (as in real) 60 without assploding. Buzzy, but it didn't banana the pushrods or shed a valve.

I do have to wonder if you've got the fuelling right. A cone filter and straight through exhaust - is the carb and jetting up to it?

If so, have you tried up-gearing? The copybikes do seem to be geared fairly low.
____________________
Biking is 1/20th as dangerous as horse riding.
GONE: HN125-8, LF-250B, GPz 305, GPZ 500S, Burgman 400 // RIDING: F650GS (800 twin), Royal Enfield Bullet Electra 500 AVL, Ninja 250R because racebike

[69chris]

the old carb was buggered so instead of buying a std replacement i bought a slightly bigger carb (24mm ? cant remember) that was sposed to be for a 140 pit bike,

going on the thinking that pitbikes run crappy cone filters and noisy exhausts was my only reasoning

to be fair to my rash choice iv done a few plug chops and it does seem to be running right, maybe a tad rich at idle/very low revs but ok elsewhere

the gearing is now cg, mainly as the cg wheel came with a new sprocket already fitted so i just bought a matching front along with the new chain

[Nobby the Bastard]

[69chris]

[Robby]

Your complaint is about poor performance.

You're running a cone air filter, a straight-through exhaust, and a random pitbike carb. This is not conducive to giving the engine exactly the right amount of fuel and air, all the time.

Plug chops won't tell you much. You can get an idea of whether the fuelling is generally rich or lean, but it could well be lean at a quarter throttle and rich at three quarters throttle.

I would start off by fitting the right carb, with the right settings and jet sizes.

[69chris]

[wr6133]

The 253FMM roger suggests would physically fit the space. You'd have to chop about and weld the mounts though (Its a copy of the Honda 233 twin, which has the same mounting points as the 125 twin). I had one in my Jinlun 250 and it pulled that bloated lump to a few Mph under 80, in that pushbike you've built I suspect it would be fairly fast.