CG 125 giving grief

[daslandroverm...]

Having a bit of grief with my Honda powered machine at present.

The short back story is thus;
The Bike is a SYM Husky that came to me part way converted to run a Honda CG125 lump.
The previous owner had got as far as installing it in the frame and connecting things as such that a squirt of easy start would see it run when kicked over.

I stripped and cleaned the carb, and set it up along with fitting a manual fuel tap to replace the vacuum one that was there to start and for a while had it running like a sweetie.

Some road miles saw it going ok until it started stuttering under load as though there was a lack of fuel, followed by it cutting out completely and refusing to re start
A near full tank of fresh stuff suggested the problem was carb forwards, a check of the plug revealed it to be dry so I stripped and cleaned the carb again, and although still not running I now have evidence of fuel getting into the cylinder.
Turning it by hand there appears to be good compression, whilst the plug out to test it (gapped at 15 thou) produces what I'd address as a strong blue spark.

The only other symptom presented was a bit of a rattling sound that seemed to be coming from inside the flywheel/drive sprocket cover, something I put down to finding the chain had slackened off a little.
I can't actually remember if it did it again on the short run before it cut out and refused to run.

Not sure on the age of the engine, but the side cover has CDi cast into it and it's kickstart only.

My thoughts are it's ignition related, but as my experience of carburettor petrol engines relates more to Rover V8's and other Land Rover engines I thought I'd ask and see if someone with more knowledge of these little things can help me in the right direction.
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Experimenting with 2 wheels

[WD Forte]

Just a guess but regarding the rattling co-inciding with its ailing.
I'd remove a cover and check the rotor hasnt worked loose on the shaft
Seen it happen before and there was spark but the timing was out
Just a guess ok? wont hurt to check
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bikers smell of wee

[daslandroverm...]

Pulled the drive sprocket/flywheel cover and had a look again. There's evidence of the flywheel having made some contact with the cover, the how I'm not so sure on as there doesn't feel to be any float in the thing (pulling on it mighty hard to test the theory!!!) And no movement when pulling the clutch lever, although I'm not sure that would affect it?

Is there a simple way of checking the ignition timing is right?
The timing slug on the flywheel is under the pickup when the 'F' mark lines up with what I presume to be the timing mark on the engine, although spinning it over on the lever by hand reveals that the timing slug is nowhere near the pickup when it makes a spark, although it seems to be on a compression.
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Experimenting with 2 wheels

[unitynotsocri...]

It maybe a Woodruff's key problem,which is a metal wedge that holds the flywheel on the crankend.

Its common for them to be tightened up while not fully in the slot , using big spanners to tighten the flywheel bolt just flattens em.

Remove the flywheel and check the key and the slot.
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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

[daslandroverm...]

Spoken to the previous owner of the thing, seems the flywheel and a few other bits were bought separately as the engine e didn't come with them.

Knowing the guy who assembled it all I'm thinking it could well be the flywheel having moved on the crank.

Fuck.
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Experimenting with 2 wheels

[unitynotsocri...]

Just remember map and Chinese flywheels , and most other cg copy stuff is not compatible .Early Honda cg s had 6 volt electrics and the flywheels are not comparable with later cg s. .

Make sure the Woodruff's key is OK and the flywheel is correct for the engine.
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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

[daslandroverm...]

The engine is all correct parts for its age (post 1995 CDi lump) althoughlooking to remove the flywheel this morning found the retaining nut was loose (How the hell I missed that!?!?!?) and as suggested the key was absolutely mullered.

The keyway in the flywheel is fine, there's a little fretting on the crank, but I'm confident it's ok to go back together with a new key, one of which I have on order from the local Honda dealer which will arrive Monday.
It'll go on torqued up properly (anyone got the book figure?) with a healthy blob of loctite on the threads.

All being well it should return to its running ways.
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Experimenting with 2 wheels

[unitynotsocri...]

Handy hint........buy two Woodruff's keys.

When tightening up the flywheel keep your eye on alignment.Many a duffo haaaave gone mad with a tourque wrench or scaffold bar on the flywheel bolt..........without checking the key sits right...

Good luck.
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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

[daslandroverm...]

Picked up a new key from my local Honda dealer earlier (a staggering £1.80 +VAT!!!) which was fitted with some care and attention -I do have something of a reputation as a decent mechanic- and tightened up to what I felt was a reasonable torque with a blob of loctite to keep it all together.

It's now running again and I'd say ready for an MOT. Now to find a little bit of time to get it done...

Thanks for the advice chaps.
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Experimenting with 2 wheels