cbx 250 keeps conking out :-s

[veze]

hi, i was riding my cbx 250 to work the other day, i was in top gear, chugging along, then all of a sudden it felt like i was running out of fuel, so i switched to reserve with no avail it conked out. my immediate assumption was check for fuel in tank, and theres loads. i took it to a mechanic but he was no help at all. he said he cleaned the carbs, which made it a little better. so i rode it home, but it has no power at all it just splutters like its running out of fuel, though it will idle absolutley fine. This is what i myself have tried.
ive checked for fuel, ive ran it with the fuel cap off, ive checked theres fuels coming out of the tap, ive screwed that little pot of that tap that seems to be the fuel filter off the tap, and cleaned the crap out of there, ive put a new fuel hose on with a new in-line filter, ive checked for spark, put a new plug in, checked for kinked pipes, im stumped. the other things i was going to do today was see how it runs withought the air filter. the thing that got me yesterday was, when i switch the fuel tap on, fuel comes out. but when i put a new clear house straight from the tank to the carb, then switched it on, no fuel came through until i started it. any help woud be fantastic!
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[veze]

rite ive had the carbs off, and there was loads of crap in the float bowls, so i think i will be having words with that mechanic. ive blew the jets out and put it all back together, it is a little better, almost rideable, but its still bogging down and cutting out when you open the throttle. maybe air/fuel mixture? im not familiar with these carbs though.
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[veze]

no one
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[veze]

no one
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[Moo.]

I get similar problems sometimes, usually after really bad rain.

An odd say it solves itself, i undo the bolts holding the carb onto the engine a little.. then it runs perfect after.

I cant explain why.. or that this will help you in anyway..


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A2 Passed 18/6/10

[veze]

rite well ive had the carbs to bits and they look fine, so im going to opt for checking the coil me thinks, does the coil have to earthed to the frame? if mine has a bad earth maybe this could be causing it??
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[Robby]

The CBX250 probably has a fairly similar wiring loom to the CB250RS, which I'm extremely well acquinted with.

First port of call is a new spark plug, and it's probably worth fitting a new HT lead and plug cap as well. Those are the service items in the ignition system and should be changed first.

The coil does earth through the frame, so pop the coil off and make sure you have good clean metal on the coil and frame to get a good earth.

Check the earth points on the frame (green wires). From memory the one nearest the coil either bolts onto the coil mounting or onto the reg/rec mount on the other side. Again, clean bright metal on both mating surfaces.

Also make sure the battery connection is good. If it's like the CB250RSD, then the battery negative only connects to the frame earth, so that lead needs a good connection to the frame and to the battery.

This is assuming it's electrical, which it probably is. Another possibility I'd think of is water in the fuel. Easiest way to check is to drain a litre into a jug from the fuel tap set to reserve, and see if there's any water in there. If there is, drain the carb float bowl then reconnect the fuel line. I pop a splash on meths into a tank that I suspect has weater in, meths is supposed to bind with the water and make it vaguely combustible.

[veze]

cheers robby, i have tried to get a good earth against thw frame, i did suspect it because my girlfriends dad had the same problem with his honda tl 125. but it didnt work, so ive got on the blower to david silver spares, and orederd one, i will let you know how i get on. i dont i know where we would be without david silver spares in this house, theyve helped us with soooo many bikes, well recomended to any honda enthusiast!!
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[veze]

rite, i have made progress! i got the coil from david silver and fitted it, but still have the same problem of 'fuel starvation'. ive swapped pulg caps with one i know is good but it still hasnt cured it. there is a new plug in, so i checked for sprak with the plug against the frame, and the spark seems to fire all over the end of the plug, even though there is a good spark. there is a part of the loom that traces along the frame, it was not fastened down properly and when i turned the engine ove i seen that there was a spark tracking across from the engine to the wireing loom. so i tied the loom back securley and that did make a difference, the bike starts now, and is back to ticking over, but still feels like fuel starvation when u rev it then it conks out again. i followed the negative off the battery to find where it was bolted. on inspection, the end of the wiring is partialy showing and it is partly broken and freyed but not completly snapped, thoough the is a connection. could it be that this needs replacing with a bit of better wire? could this be giving the bike a bad earth altogether?
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[Alex A]

Have you got a photo of the frayed wire?

Shouldn't think it's electrics related if it's not the coils. Have you checked the signal at the coils - should give a clear reading right up the rev range?

Apart from electrics, a good 20 mile run on the motorway at 70mph should help clear any carb related issues.
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Current: Ducati Panigale R / Ducati Streetfighter S / Suzuki GSX-R1000 L5

[stinkwheel]

Maybe teaching my granny to suck eggs. But if there was a load of crap in the float bowl, that means said crap came through the fuel filter and petrol tap.

They are just as likely to be gummed up. So your symptoms like fuel starvation could be fuel starvation. I'd get the tap off and give it a good clean (dismantle it if possible, blow through with compressed air if not) along with the filter. If there was a lot of grot in them, I'd consider giving the tank a good swill out too.

Most petrol taps have a rubber washer in them with four holes in directly under the part you turn. These can sometimes get all burred up and obstruct the fuel flow.

Might be worth fitting an inline filter if the inside of the tank has residual muck in it (won't stop it blocking the tap but it'll keep it out of your carbs and you'll be able to see the fuel flowing).

Another thing that can cause fuel starvation is a blocked tank breather. Air can't get back in as the fuel escapes, a vacuum forms inside the tank preventing the fuel getting out properly. Try running it with the fuel cap open. If the symptoms go away, this is your problem.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[veze]

i have cleaned the bowl on the fuel tap, and put on new in-line filter in, ive ran the bike with the tank off all together, feeding fuel to the carbs, i have cleaned the float bowls and blew the jets through, separtated the carbs and cant see any blockages. but it made no difference.
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[stinkwheel]

[deliriousthun...]

This will seem a stupid suggestion. It is a stupid suggestion. Tantamount to checking that the kill switch isn't on when trying to start a dead engine.

Nevertheless, I will make it, maybe you can laugh at it, or just maybe you will do this

Did you have the choke on full? If so, did you turn it off again?

In other words, are you flooding the engine?
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Tom

[veze]

Im gunna clean the tank out today, since i cant see it being anything else. thanks for yoy advice, will let u know how i get on guys cheers
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[veze]

just cleaned the tank out and the tap and gauze but it hasnt made any difference
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[neil.]

Fuel hoses ok, not blocked/kinked etc?
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CBT February 2008 | A2 June 2008 | Yamaha YBR125 (written off) | Honda CBF125 (current)

[veze]

nope, no kinks, could it possibly be the cdi unit?? oh and after letting it idle, when i check the plug it is alwasys sooted up
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[temeluchus]

flooding? blocked air filter, choke stuck on?
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Some shite cruiser. Now with guns and FREEDOM!

[veze]

ive ran it with the air filter off and it still does the same. how would i know if the choke was stuck on ?
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[temeluchus]

is it a cable (ie goes to the handlebars) choke, or a knob on the carb?

Either way, it will operate a little plunger, this should move in and out of the carb as its operated. In is off, out is on.

also, get the bottom off the carb and inspect the float needle. Check it hasnt "shouldered", basically worn a notch in its point, which will allow too much fuel in and can cause the problems described.
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Some shite cruiser. Now with guns and FREEDOM!

[veze]

the choke operates fine, so it must be running rich then, when an engine is running rich, how come the plug is sooty and dry?
and another thing, if the problem is running rich, then why would it suddenly change while i was riding it to work and do it all of a sudden? cough, plutter and conk out all the time previous, after miles of faultless and perfect fuctioning?
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[temeluchus]

When the mix is just right it is hot enough to burn the carbon from the sparkplug, too rich and it runs too cool, letting the carbon foul the plug. Liquid fuewl will build up and earth the plug so it doesnt spark. This can take a while depending on how rich.

The engine will run somewhat rich for quite a distance before it becomes a problem.

You probably want to see if there is a rebuild kit for your carb, or purchase a new carb entirely.
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Some shite cruiser. Now with guns and FREEDOM!

[veze]

i just dont get how it can be running absolutley fine then all of a sudden do that?, surely a problem like running rich will occur gradualy??
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[N cee thirty]

this happened to my cg today,but toke the air filter off and it ran :S
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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