cg epic backfires

[N cee thirty]

does actually sound like a shotgun

came back from the mechanics today where he'd set up the points after i'd fitted a new stator plate,after about 3 or 4 miles it started running really bad and if i came to traffic lights it would cut out.

rode it tonight and went about 5mph constantly backfiring.

came back and was fine under certain revs,but once you went over about half throttle it would just backfire

whats up with it??

the indicators work when they want to,hows this sorted ?

cheers
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'00 Aprilia RS50 > '92 Honda CG > '99 Yamaha Fazer > '91 Yamaha RXS > '79 Suzuki X5 > 01' Honda Cg > 07' Honda Cg > 82' Kawasaki Z200 > suzuki gsxr 400 gk73a > honda vfr 400 NC30 Mod 2 Passed 09/06/2011

Jewlio Iglesias wrote: I actually did vote BNP once

[truslack]

Can you define what you mean by a backfire - do you mean a backfire (through the carb) or combustion in the exhaust, causing flames to shoot out of the silencer? (which I'm pretty sure is NOT a backfire)
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Current: Suzuki RG 125 Gamma, Honda H100, Triumph Tiger 800XC, Suzuki SV650 (minitwin)

[N cee thirty]

well not quite backfiring,its popping alot especially at higher revs
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'00 Aprilia RS50 > '92 Honda CG > '99 Yamaha Fazer > '91 Yamaha RXS > '79 Suzuki X5 > 01' Honda Cg > 07' Honda Cg > 82' Kawasaki Z200 > suzuki gsxr 400 gk73a > honda vfr 400 NC30 Mod 2 Passed 09/06/2011

Jewlio Iglesias wrote: I actually did vote BNP once

[Ariel Badger]

[skatefreak]

Interestingly i have found my 2-t NSR dosnt so much backfire as much as it will occasionally *queef* haha.
That said, the 4t 125 sometimes backfired and it to sounded like a shot gun

No idea how this could be caused when the engine is running though, especially at higher rev's so not much else of use to add here so i'll go with the above advice..

Best regards

-Jvr

[N cee thirty]

its pretty intermitent

yesterday i was going along and went up to some traffic lights and it kit out,after about 10 kickstarts it went and ran really well for about a mile and then cut out at home
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'00 Aprilia RS50 > '92 Honda CG > '99 Yamaha Fazer > '91 Yamaha RXS > '79 Suzuki X5 > 01' Honda Cg > 07' Honda Cg > 82' Kawasaki Z200 > suzuki gsxr 400 gk73a > honda vfr 400 NC30 Mod 2 Passed 09/06/2011

Jewlio Iglesias wrote: I actually did vote BNP once

[robocog]

IME
coughing or spitting through the carbs is one sign of weak mixture
igniting through the exhaust can be a symptom of an air leak on the exhaust system

but as your guy has fitted new points (which on a CG would not require footling with either carbs nor exhaust system) I would have thought is more than likely the fault is to do with whats laying behind the stator

could be he's not nipped the points up and they are "wandering" causing wonky and possibly intermittent timing ?
(or overtightened them and a head has sheared off?)

Could also be that the wire that connects to the points has come adrift and is being intermittent or the wire has snapped and has become random?

First port of call would be to contact the garage and see what they suggest as there could potentially be a loose bolt in there (if one has come out completely) which could cause £££££ problems in riding the bike much further to get it looked at

Maybe worth pulling the cover off and using a torch to see if the points are properly screwed down and both bolts are present and correct before riding it again??

Regards
Rob
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Needs a bigger garage...

[N cee thirty]

hmm its pretty weird,its fine under 1/3 throttle and sometimes at full throttle but other than that it pops like buggery
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'00 Aprilia RS50 > '92 Honda CG > '99 Yamaha Fazer > '91 Yamaha RXS > '79 Suzuki X5 > 01' Honda Cg > 07' Honda Cg > 82' Kawasaki Z200 > suzuki gsxr 400 gk73a > honda vfr 400 NC30 Mod 2 Passed 09/06/2011

Jewlio Iglesias wrote: I actually did vote BNP once

[stonesie]

That's sounding more like a carb problem to me, have you had a look at the plug colour? also if you have access to a timing light you can check how it has been set, retarded timing causes hot running and pretty impressive backfires but you would have noticed the lack of power that goes with it.

[N cee thirty]

[N cee thirty]

well been on a fair ride out and toke the plug out and its really sutty now :S

also it pops about half throttle but at full its fine
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'00 Aprilia RS50 > '92 Honda CG > '99 Yamaha Fazer > '91 Yamaha RXS > '79 Suzuki X5 > 01' Honda Cg > 07' Honda Cg > 82' Kawasaki Z200 > suzuki gsxr 400 gk73a > honda vfr 400 NC30 Mod 2 Passed 09/06/2011

Jewlio Iglesias wrote: I actually did vote BNP once

[stonesie]

I would try moving the clip on the carb needle up one notch to lean it out a little in the mid range, easy to pop it back if it doesn't work or one the other way if it makes it worse


I found this for the Keihin carb's to show what bit affects what...
https://asulaeman.files.wordpress.com/2008/04/tuningcarb2.gif

[Chalky.]

Why haven't you taken it back to the mechanic who did the work in the first place?