[:@] $$$ wasting away, I just had the Carb rebuilt had a petcock replaced and when the bike and petcock is shut off I am still losing gas out of the overflow tube,&nbsp\\; any suggestions?[]

 

I just had the Carb rebuilt
Are you sure the needle valve is sits properly? Even a bad fuel petcock will not cause the carb to flood, know what I mean? It could be stuck.

 

Exactly what overflow tube are you referring to? If the petcock is shut off, unless it's defective, there is no way you can be leaking fuel from the carb. bowl overflow. Maybe the fuel tank vent line?

 

Yeah, that is what I was thinking - if the petcock is shut, there can't be much fuel to leak.

 

Hello everyone. I am new to the forum and just bought my first HD, a 97 1200 Sportster, but I am not new to wrenching on everything from cars to British twins and metric bikes. Just my 2 cents but if you just had the carb rebuilt and the petcock replaced I'd be calling the guy who did the work and bring it back to him to get his take. A rebuilt carb should not be leaking if the float bowl is set properly and the float needle valve is fitting properly. Also there should be no fuel flow with from the petcock with it shut off.
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The petcock is easy to check. Get yourself a plastic cup or anything but glass and pull the fuel line loose and see if any fuel drains into the cup. If this is a newer style vacuum petcock no fuel should flow if the engine isn't running. It relies on engine vacuum to pull a diaphram to let fuel flow. Just cranking the engine should generate enough vacuum to make the petcock work.
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As for fuel overflowing from the carb that is a serious problem as raw fuel will work it's way into the cylinders and wash them causing massive wear just cranking the engine, let alone a dry start. In extreme cases it will fill one cylinder and cause a hydro locked engine. Could easily bend a rod or blow a head gasket. Remove the spark plugs before cranking the engine and if raw gas shoots out of the spark plug holes you had, or were very close to having, &nbsp\\;a hydro locked engine.
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I would suggest that if there is any doubt in your mind, that the carb is overflowing, take it back to the person that did the rebuild and let him know.

 

Yes it is the fuel tank vent line, and the petcock was in the shut off position,they had to put a vise grip on the petcock hose, don't know what that is supposed to do if it was comming out of the fuel tank overflow hose?&nbsp\\;I sent you a email from my att. account don't know if you got it, but after reading what jdvorchak say's I'm really scared there going to blow my engine. They did a Dyno test run on it earlier and it was pushing 85HP it's a 87 Scremin Eagle Sportster 883 bore out to 1200 the Damm thing has been nothing but problems since I bought it.

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Just a long shot here but does it have the correct gas cap?&nbsp\\;\\\\\\; Vented?&nbsp\\;\\\\\\; Or non-vented?
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Does the petcock have a vacuum lock on it?&nbsp\\; Is it hooked up to the vacuum line?
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Even still, I have an aftermarket petcock that does not have the vacuum safety lock on it... every now and then I will forget to turn it off when putting the bike away and I never have any gas run-out.&nbsp\\; I would say you probably have a torn accelerator pump diaphram or as mentioned a needle that is not seated properly.&nbsp\\; The most common parts to damage when cleaning a carb are the accelerator pump diaphram, or the vacuum piston diaphram.&nbsp\\; Also, if the float angle is incorrect during re-assembly you will end up with constant overflow.
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But from what you are saying, FUEL is leaking from the GAS TANK vent?&nbsp\\; If that is the case, your gas cap is most likely defective or the vent tube through the tank is rusted out.&nbsp\\; The vent tube runs through the tank and is the little tube you see in the fill tube when you remove the fuel cap.&nbsp\\; If that tube is rusted out or damaged...it will leake fuel from your tank into the tube and out the vent hose.&nbsp\\; Squeezing off the fuel line would cause an airlock and stop the leaking.&nbsp\\;&nbsp\\; I think if that is the case, tested by removing the tank from the bike, remove the petcock, plug the hole and run some fuel into the tank...if it leaks out the vent line, it has a hole internally.. I doubt there is a fix...time for a new tank.&nbsp\\; You may be able to cap off the vent and use a vented CAP to relieve the pressure in the tank..&nbsp\\;
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When I went to a third party gas tank, none of them are vented..and they don't leak.&nbsp\\; You have to use a VENTED cap with them though...&nbsp\\; So like I said above, you should be able to plug the vent and go with a VENTED cap.&nbsp\\; If you dont use a vented cap...an air lock will develope and fuel will not flow...&nbsp\\;&nbsp\\; Just one of the perks to a gravity fed fuel system.&nbsp\\; Personally, I wouldnt have it any other way..

 

The bike has a different gas tank on it, not a stock one so I don't know if it needs a vented gas cap or not, but I will ask the guys at the shop if it needs one , you have been very helpful, I had 2 other bikes but I had to sell them to pay for the repairs on this thing, right now I'm over $1,700.00 in repairs.
I had 2 450 Rebels 1986 and was never in the shop/ they looked like lil Sportsters so I decided to go out and buy a 87, wrong move. I'll try to send a pic of the tank I took a pic. of it cause it had gotten a new paint job, maybe there is paint flecks in the tank.??

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Not a wrong move.&nbsp\\; Once you get the issue resolved and fix someone elses neglect (Not HDs) you will see the Sporty is 10X the rebels.
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If it's leaking out the vent hose, its most likely a vent pipe with&nbsp\\;a hole in it.&nbsp\\; Easy test, connect a vacuum hose to the vent that is located at the bung where you screw the gas cap in.&nbsp\\; You will see a tube sticking up. (see attached photo) Clamp off the vent hose thats leaking... Blow into the end you connect to the the tube..&nbsp\\; You should be able to feel the resistance as being solid (no leak) or air pressure dropping (leak).&nbsp\\;
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If gas is leaking out the vent, it has to have a hole in the vent tube inside the tank somewhere.
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The vent tube SHOULD only dump gas if you over flow your tank...and I mean WAY overflow your tank.&nbsp\\; The vent is meant to leak AIR, not gas.&nbsp\\; This prevents vacuum lock in your gas line which is a gravity feed system.&nbsp\\; If this is the case and I believe it is, your only options are to remove the tank and install a new tank or plug the vent where it leaves the tank on the bottom and use a VENTED cap.
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Most importantly, let us know how it turns out.

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&nbsp\\;Well I hope they fixed the problem, it seems that there were 3 lines of the over flow tube, the problem 1 was going from the fuel canister into the carb, so when the tank got hot it would dump fuel into the carb and then **** it out into the over flow tube, so they disconnected it,the petcock was fine. I guess they used to use 3 lines about 10yrs. ago but since there is a vent cap on the gas tank I didn't need the 3rd line anymore. Thanks to all of my HD friends for your help in this matter.&nbsp\\;I will keep you up on my rides if a problem arises with this new fix.