Leaking gas out of carb

Super

New Member
Sep 19, 2011
39
0
0
Texas
Hi everyone. My carb is leaking gas out the air filter and it also runs though motor and runs out exhaust pipe. I've taken everything apart and it all looks fine. No gas in float, float level is right, and no trash in the carb. That only leaves one thing, I think, and that is the float needle is not seating right. I checked it and to the necked eye it looks fine. I blew out the hole the needle goes into. Nothings worked so far. My question is, can the float needle or the hole the float needle seats against go bad form normal wear and tear? And, can it be repaired or do I have to buy a whole new carb seeing as how I don't know if the needle is bad or the spot it rests against is bad? Any ideas or suggestions?

I know I can just turn off gas to stop this. But because I'm not used to this, I keep forgetting and after work I hop on my bike to return home and I have no gas to return home with. Motor runs fine, just having major gas leakage.

Oh and ps I have the NT Carb
 
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2door

Moderator
Staff member
Sep 15, 2008
16,325
114
63
Littleton, Colorado
Simple test. Remove the float bowl, turn the fuel pet cock to the open position and gently push up on the brass tangs that the float rides against. If the fuel stops flowing, everything is working. If it doesn't stop and continues to dribbel or drip you've found the problem. The needle and seat aren't working or you don't have the float level adjusted correctly. Find out.
My advice? Don't forget to shut off the fuel when you're not riding. Even if things work right it only takes a very small piece of crud to block the needle. Are you using an in-line fuel filter? You should be.

Tom
 

Super

New Member
Sep 19, 2011
39
0
0
Texas
Simple test. Remove the float bowl, turn the fuel pet cock to the open position and gently push up on the brass tangs that the float rides against. If the fuel stops flowing, everything is working. If it doesn't stop and continues to dribbel or drip you've found the problem. The needle and seat aren't working or you don't have the float level adjusted correctly. Find out.
My advice? Don't forget to shut off the fuel when you're not riding. Even if things work right it only takes a very small piece of crud to block the needle. Are you using an in-line fuel filter? You should be.

Tom
I will try this but I'm already pretty sure it is NOT seating right. But my question was; How to fix it, if it is not seating right? The needle dose not look corroded at all but to be safe, I did rub a Brillo pad on it. Not sandpaper because I was afraid of causing abrasions in it. The hole the needle goes into, I can't get to. But like I said, i did blow it out with a air hose. Or, do I just need to buy a new carb?

BTW I love the NT carb. I've had very little problems with the carb until now. It's about a year old and is uses on a daily basis. And It still looks as new as the day I got it.

Oh and yes I have an inline filter. Just change it actually, about 2 weeks ago.
 
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bigbutterbean

New Member
Jan 31, 2011
2,417
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Lebanon, PA
I know I can just turn off gas to stop this. But because I'm not used to this, I keep forgetting and after work I hop on my bike to return home and I have no gas to return home with. Motor runs fine, just having major gas leakage.

Oh and ps I have the NT Carb
Simple solution? Remember to turn off your gas. My first carb did the same thing. I remember to turn off my gas, no more leaking.
 

Super

New Member
Sep 19, 2011
39
0
0
Texas
Simple solution? Remember to turn off your gas. My first carb did the same thing. I remember to turn off my gas, no more leaking.
It's not that simple. I would have to shut gas off every time I stop even for a minute or so. Stopping even for a short period causes an over flow and floods the motor with fuel. Then it is hard to start when I get back. It's an inconvenience that I refuse to live with. I'd rather get it fixed or rig up an on/off key that also shuts the fuel on and off. .bld.

All I'm asking is:
My question is, can the float needle or the hole the float needle seats against go bad form normal wear and tear? And, can it be repaired or do I have to buy a whole new carb seeing as how I don't know if the needle is bad or the spot it rests against is bad? Any ideas or suggestions?
 

JonnyR

New Member
May 13, 2012
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ronkonkoma, new york
It's not that simple. I would have to shut gas off every time I stop even for a minute or so. Stopping even for a short period causes an over flow and floods the motor with fuel. Then it is hard to start when I get back. It's an inconvenience that I refuse to live with. I'd rather get it fixed or rig up an on/off key that also shuts the fuel on and off. .bld.

All I'm asking is:
the petcock is a on off key but i know what you are saying you want it to work.
i say replace it its $10 or so plus shipping

http://www.ebay.com/itm/Motorized-B...328?pt=LH_DefaultDomain_2&hash=item416b39ad88
 

rustycase

Gutter Rider
May 26, 2011
2,746
0
0
Left coast
See what happens when you do the simple test 2dr suggested...

Sometimes the needles just won't seat properly for no apparent reason...
two or three times fiddling with it and it may just kinda fall into place and you'll never have a problem with it again.

The HT petcocks that come with the kits can not be trusted.
All the ones I have seen leaked when in the off position.
It was necessary to replace 'em with an alternative from another source.

Good luck
rc
 

Super

New Member
Sep 19, 2011
39
0
0
Texas
Well I just tied the needle test suggested earlier and with the smallest amount of pressure the gas stops. So again I check the float(no fluid inside) and the float level. Which brings me to another point. The only way I can see the float level causing a massive overflow like this is if the float went high enough for the needle not to rest against it. Which in this case dose not look possible. The float bowl is not deep enough for that.( If you don't get what I'm saying I will try to draw a diagram of what I'm talking about.

But anyways, when I put the bowl back on it still leaks. I don't understand it. It stopped with the bowl off, why not with it on?

oh and just incase your wondering my float measurement is at 25mm, 4mm higher then the suggested 21mm. That means my fuel lvl in the bowl should be 4mm lower then the suggested level.
 
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rustycase

Gutter Rider
May 26, 2011
2,746
0
0
Left coast
there may be a small amount of crud in there that floats around when the fuel is applied.

let some run out, move the tang just a tad, and maybe it will fall into place.

there's long shot you could have a bad casting for the carb, too...

In chinagirl land, anything is possible!

Good luck
rc
 

biknut

Well-Known Member
Sep 28, 2010
6,511
206
63
Dallas
I've had this problem a few times. These are some things to check.

I think you already checked the first one. Make sure the float isn't cracked, and leaking fuel inside the float.

Next remove the float needle, and look down into the seat and make sure there's not a tiny piece of curd in there. Mine had this problem a couple of weeks ago, and was leaking.

Make sure the float bowl gasket is in place, and in good condition.

If you have a hose clamp on the gas line where it connects to the carb, make sure the clamp hasn't cut through the line.

If it's not any of those things, adjust the float level so the float pushes on the needle a little harder. Don't over do it.
 

Super

New Member
Sep 19, 2011
39
0
0
Texas
Sry guys been busy with work and other stuff, hadn't had time to fool with bike for the last few days. I bought a new/used carb to try, lets see how that works.
 

2door

Moderator
Staff member
Sep 15, 2008
16,325
114
63
Littleton, Colorado
Bend the tangs down, ever so slightly and make sure they are the same. Lowering the float level can't hurt.


LOL, this reminds me of an old post from a guy with the same problem. He finally posted a picture of his carburetor..............he'd installed it upside down.
We're assuming this isn't the case here :)

Tom
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
4,484
16
0
memphis Tn
Whatever the cause, your needle is leaking. A brillo on the rubber tip did not help matters...Try a new needle if all else fails.
 

TheRealDune

New Member
Aug 2, 2013
67
0
0
Las Cruces,NM
Well I just tied the needle test suggested earlier and with the smallest amount of pressure the gas stops. So again I check the float(no fluid inside) and the float level. Which brings me to another point. The only way I can see the float level causing a massive overflow like this is if the float went high enough for the needle not to rest against it. Which in this case dose not look possible. The float bowl is not deep enough for that.( If you don't get what I'm saying I will try to draw a diagram of what I'm talking about.

But anyways, when I put the bowl back on it still leaks. I don't understand it. It stopped with the bowl off, why not with it on?

oh and just incase your wondering my float measurement is at 25mm, 4mm higher then the suggested 21mm. That means my fuel lvl in the bowl should be 4mm lower then the suggested level.
please make a diagram for complete understanding
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
4,484
16
0
memphis Tn
Fangs? Maybe the OP got a hold of a "Vampire" carb.
You know, the one that slowly bleeds you to death.....