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Slight carb problem


wyliecoyote
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Hello everyone,

having a little problem with my carb!any help appreciated! i have a yz 125 and whenever i turn the petrol on, petrol pisses out of a breather pipe. the pipe is on the bottom of the carb and it comes from the casing that houses the float. ive searched the internet and it seems i need to adjust the float? is this a normal thing to have to do? the bike is a 1998 by the way!!

Thanks!

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Hello everyone,

having a little problem with my carb!any help appreciated! i have a yz 125 and whenever i turn the petrol on, petrol pisses out of a breather pipe. the pipe is on the bottom of the carb and it comes from the casing that houses the float. ive searched the internet and it seems i need to adjust the float? is this a normal thing to have to do? the bike is a 1998 by the way!!

Thanks!

could be your needle in you float valve sticking , or the float is goosed , pull the carb off and take out the float stick it in a bowl of water and see that it definatley floats if it sinks its goosed ( make sure you dry off before putting back on )

if you have not touched the carb and it was ok before i think it will be the float valve sticking ,take it out and spray with wd40 and work it in and out check the point end too there should be no grooves, ruff bits on , for what its worth just order a new float valve if i were you

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the pipe is on the bottom of the carb and it comes from the casing that houses the float.

Do mean the very bottom of the carb (ie. float bowl).

If so,,,,do as KirriePete is saying !

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Just a thought - the float bowl drain screw is done up properly, isn't it?

Thanks for the input lads!

if the float bowl drain screw is the big screw on the bottom of the casing, then yes that was done up properly! the bike was running fine before this happened. unfortunatly ive have a very basic knowledge of this kind of thing! not to worry though, im sure ill get it sorted!

Thanks

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Do mean the very bottom of the carb (ie. float bowl).

If so,,,,do as KirriePete is saying !

Thanks for the reply

no its not the screw that the petrol is coming from, its a gold spout that comes from the "float bowl" and it turns at 90 degress. when i cover it with my finger, petrol starts coming from a differant overflow pipe!

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Well then,,,dirt must have got through in the fuel,,,,,,or the bike was left unused for a while.

The float valve is sticking by the sounds of it.

Carb off

float bowl off

carefully move the float up and down by hand without bending it

if you can, blow through the valve to clear it out

put back togeather

You could try lightly tapping the tloat bowl with something first to see if it free's it up before you take carb off.

Best of luck !

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Well then,,,dirt must have got through in the fuel,,,,,,or the bike was left unused for a while.

The float valve is sticking by the sounds of it.

Carb off

float bowl off

carefully move the float up and down by hand without bending it

if you can, blow through the valve to clear it out

put back togeather

You could try lightly tapping the tloat bowl with something first to see if it free's it up before you take carb off.

Best of luck !

yep done that before and it works , it might be a tiny little speck of dirt that lodged in the bowl

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Thanks for the reply

i just took the carb apart there twice, cleaned it out and put it back on the bike. gave a few kicks but no joy, but the petrol stopped flowing out!

so, toke of the spark plug and it was fouled, cleaned it and tested it against the rad to make sure there was a spark and it still wont start!

will a spark plug still work after being fouled??

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Thanks for the reply

i just took the carb apart there twice, cleaned it out and put it back on the bike. gave a few kicks but no joy, but the petrol stopped flowing out!

so, toke of the spark plug and it was fouled, cleaned it and tested it against the rad to make sure there was a spark and it still wont start!

will a spark plug still work after being fouled??

The rad might not be earthed as it usualy sits on rubbers so that it cant vibrate and burst,,,,,,,,,earth the plug on the side of the engine.

How long has this bike been layed up,,,,,if at all ?

EDIT: start at the tank make sure fuel is getting to the carb,,,,,open drain screw/nut on bottom of carb and let fuel flow out,, then tighten.

no plug in then kick her over a few times, then plug in and choke on, no throttle,,,,,,give her a good kicking. All this of coarse only if ya have a spark. If it still wont start,,,,plug out to see if its wet with fuel !!!

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The rad might not be earthed as it usualy sits on rubbers so that it cant vibrate and burst,,,,,,,,,earth the plug on the side of the engine.

How long has this bike been layed up,,,,,if at all ?

EDIT: start at the tank make sure fuel is getting to the carb,,,,,open drain screw/nut on bottom of carb and let fuel flow out,, then tighten.

no plug in then kick her over a few times, then plug in and choke on, no throttle,,,,,,give her a good kicking. All this of coarse only if ya have a spark. If it still wont start,,,,plug out to see if its wet with fuel !!!

the bike has been sittin up a while! im just after gettin a top end rebuild and im now finished breaking it in! however, i was told that around a half an hour is enough for a break in, but i only get a chance to drive it for about 5mins at a time, so it was broken in over a few weeks! and we just had about 2 weeks of snow with minus 10 degrees!!

there is defo fuel gettin into the carb because i took it back out to make sure there was fuel in it and there was! as i said before, the spark plug was wet, so i cleaned it and tried again, still no joy!

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the bike has been sittin up a while! im just after gettin a top end rebuild and im now finished breaking it in! however, i was told that around a half an hour is enough for a break in, but i only get a chance to drive it for about 5mins at a time, so it was broken in over a few weeks! and we just had about 2 weeks of snow with minus 10 degrees!!

there is defo fuel gettin into the carb because i took it back out to make sure there was fuel in it and there was! as i said before, the spark plug was wet, so i cleaned it and tried again, still no joy!

Break in miles for a newly rebuilt engine is far more that half an hour,,,

If ya have no sark with it earthed on engine then try a new plug.

No spark after that then you have to trace the lead back to where there is power comming to it,,,,,( ie. coil )

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I was just re-reading and i dont know if ya have a spark now or not ?

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