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Carb leaking fuel

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I have a 2011 ktm 150sx .The bike has been sitting over the winter. I turned on the fuel as i was going to start it up and the fuel was coming out of the hose from the bottom of the carb. I lightly tapped the bowl but it didn't help.So i ripped the carb off and everything looks super clean inside. The float bowl is moving fine. This is the first carb i have took apart so I don't really know what I'm looking for. Is there a good tutorial i could watch on this keihin carb? thanks

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it could have just been a little film or dirt at the float valve that was holding it open and letting it over flow

 

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Yep, has to be the float needle valve or its seat.  You may have to replace it.  hold the carb body upright, blow into the fuel line input, and softly raise the float. It should easily shut off your air flow when you feel the slightest pressure on the float against the needle.

Something else to check, and it is kind of rare, a float that doesn't float usually from being cracked and filling with gas.

Edited by wielywilly-g
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7 hours ago, wielywilly-g said:

Yep, has to be the float needle valve or its seat.  You may have to replace it.  hold the carb body upright, blow into the fuel line input, and softly raise the float. It should easily shut off your air flow when you feel the slightest pressure on the float against the needle.

Something else to check, and it is kind of rare, a float that doesn't float usually from being cracked and filling with gas.

Look no further--you have the answers here. Your needle valve could have to be cleaned but the issues are described above.

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8 hours ago, Gmc09 said:

I have a 2011 ktm 150sx .The bike has been sitting over the winter. I turned on the fuel as i was going to start it up and the fuel was coming out of the hose from the bottom of the carb. I lightly tapped the bowl but it didn't help.So i ripped the carb off and everything looks super clean inside. The float bowl is moving fine. This is the first carb i have took apart so I don't really know what I'm looking for. Is there a good tutorial i could watch on this keihin carb? thanks

Time to learn how to set it.   If you have had it since 2011,  I am guessing the factory setting is the last setting.  

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It is also possible the O-ring around the float needle seat could be old and cracked.  Sometimes the O-ring can be replaced but lots of the time you can only buy the entire needle seat with its O-ring.

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Everything in the carb looks spotless. I cleaned it anyways and blew it out. I think the float level might be wrong. Should it be level to gasket edge at a 45deg angle? Is the o-ring supposed to be in where the float needle drops down into? I don't remember seeing one in there?

Edited by Gmc09

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wielywilly-g thanks. I did the blow test with the carb upright and when the float was level the air seemed to stop .I submerged the floats no bubbles. Set the float level, I then tested it and it still leaked. How to I get that brass valve seat out? it looks like its pressed in there. thanks

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I did the air test again with the carb upright and just before the float goes level with the gasket it shuts the air off. But what i did noticed when i move the float up and down slowly up at the light I see the float needle sometimes jump a tiny bit like its sticks a tiny bit. Maybe i should polish inside the needle seat with a cue tip?it looks clean but maybe there's a little coating of crap in there. I can't think of anything else?

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I haven't looked really closely at a seat socket in awhile.  They have improved design since the 60's, when it wasn't uncommon to see that the needle would wear the socket out along the sides,  up and down motion along with loads of vibration.  Most carburetors are rubber mounted now too, and at one time a solid flange or spigot mount was the norm.   now you still get worn needles of the viton tipped variety and the springs in them sack out too.   

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Can you post a picture of the seat?  I google your carb and lots of pics came up of different ones.  Did you look at the OEM fiche online to see if the needle and seat are sold individual?

So you blow air and it stops it, but gravity fuel and it keeps flowing.  Does the float pivot seem free?  If that tip of the needle is sticky it needs to be replaced.  You can run a q-tip down in the seat no problem, just be sure to blow out all the cotton threads.

I just got a new needle, seat, and gasket for my 1947 tractor that was leaking. $13 and it is fixed. LOL

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4 hours ago, wielywilly-g said:

Can you post a picture of the seat?  I google your carb and lots of pics came up of different ones.  Did you look at the OEM fiche online to see if the needle and seat are sold individual?

So you blow air and it stops it, but gravity fuel and it keeps flowing.  Does the float pivot seem free?  If that tip of the needle is sticky it needs to be replaced.  You can run a q-tip down in the seat no problem, just be sure to blow out all the cotton threads.

I just got a new needle, seat, and gasket for my 1947 tractor that was leaking. $13 and it is fixed. LOL

off topic,  but what tractor?

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5 hours ago, ossagp said:

off topic,  but what tractor?

It's a Farmall-H that I use to mow my 2 acer yard.  You got an old tractor?

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I don't have anything like the farmall H right now.  i grew up using those to pull trailers with irrigation pipe.  we redid an international cub,  and a late 30's case r.  All the case needed was a paint job.   a real find for alaska. this one had been put on a remote military base back in ww2 and had very little time on it.  the starter and switches were all in pretty decent shape even.  lights worked.  both got sold pretty quicktly.  I have a case ck530 diesel with a bucket and a hoe on it.  once I finish using it I think I might make it look new.  it needs everything hydraulic gone through except for pumps,  and some odds and ends.  runs sweet. diesel.  same guy that i did the case with had a very early jd crawler,  small gas job.  made it beautiful and welded new growzers onto what must have been the original tracks.  one of those things he was going to keep forever just to move the little mx track around that his grandkids were using.  he is an old skinner and was looking forward to showing them the basics.  hard to believe he couldn't tie them to it and make the work it.  he moved it to some other property he has.  He is about to turn 86,  so I need to get it away from him.  love the old iron.  

Edited by ossagp
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This is the carb I have . I did this and polished the seat up and adjusted the float and it seems to work fine now. I tested just with the fuel line hooked up with the float bowl off the carb over a bucket. thanks guys

 

Edited by Gmc09

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