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I've been fixing up this old Kawasaki I bought that wasn't running, all I did was take of the carb and replace the jets and gaskets in the carb and float needle. I got the bike running for about a week with no real issues. Then the bike started pouring out gas in the 2nd carburetor. It was coming out of the nipple of the bottom of the float bowl. I took out the carb and there was a bit of stuff clogging the needle so i cleared that out, but the carbs back in and it stopped. Then It started doing the same thing out of the 4th carb. I took the carbs out again and cleared everything out and it still was pouring gas out. I have since cleaned all the carbs again to make sure absolutely nothing would clog them but the 4th carb still leaks gas out of the nipple at the bottom of the bowl. Anyone has any similar issues that knows what I need to do to fix it?
 

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The junk that is clogging your carbs is probably coming from your fuel tank. Old bikes can have rusty gas tanks with a lot of sediment sitting at the bottom. The tank should be flushed clean, possibly sealed but at the very least, install an inline fuel filter. It's a lot easier to replace a fuel filter than to clean your carbs.
 

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Discussion Starter #3
The junk that is clogging your carbs is probably coming from your fuel tank. Old bikes can have rusty gas tanks with a lot of sediment sitting at the bottom. The tank should be flushed clean, possibly sealed but at the very least, install an inline fuel filter. It's a lot easier to replace a fuel filter than to clean your carbs.
Yes, I do have a fuel filter on the fuel line. the tank has been cleaned but it hasn't been sealed, the problem is that im not sure why the 4th carb out of all of them is getting to much gas since it shouldn't have any clogging problems anymore
 

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i have the same issue i just got the carbs cleaned by a guru but my tank is very rusty ill be getting evaporust and letting it soak for about week here soon, replace all my fuel lines and getting a new petcock and inline fuel filter before i start her up again..
 

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Discussion Starter #5
i have the same issue i just got the carbs cleaned by a guru but my tank is very rusty ill be getting evaporust and letting it soak for about week here soon, replace all my fuel lines and getting a new petcock and inline fuel filter before i start her up again..
alright can you let me know if that fixed it for you, haven't been able to solve this problem for over a month now
 

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If you coat the inside of the tank, red kote has gotten a lot of positive press on another bike site.
On my 85 ZN700, I just sloshed the gas around and dumped it to get the rust particles out and repeated. And I installed a filter and I haven't had any problems so far. This was 11 years/5k miles ago. If I have to remove the carbs I repeat the sloshing and dumping. I also filter the gasoline using a paper shop towel and put it back into the tank.
 

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Discussion Starter #7
If you coat the inside of the tank, red kote has gotten a lot of positive press on another bike site.
On my 85 ZN700, I just sloshed the gas around and dumped it to get the rust particles out and repeated. And I installed a filter and I haven't had any problems so far. This was 11 years/5k miles ago. If I have to remove the carbs I repeat the sloshing and dumping. I also filter the gasoline using a paper shop towel and put it back into the tank.
Did you have a similar problem with leaking gas
 

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alright can you let me know if that fixed it for you, haven't been able to solve this problem for over a month now
yeah but it might be about two weeks before its all said and done i got alot going on might be best for you to go ahead and do those steps anyways considering the bikes age and the problems youre having, all three are cheap and will do you good in the long run
 

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yeah but it might be about two weeks before its all said and done i got alot going on might be best for you to go ahead and do those steps anyways considering the bikes age and the problems youre having, all three are cheap and will do you good in the long run
yeah im planning on doing so, i just hope that will be the solution to this problem. every mechanic i talk too has a way different answer than the previous one, but it sounds like everyone here agrees on this
 

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yeah im planning on doing so, i just hope that will be the solution to this problem. every mechanic i talk too has a way different answer than the previous one, but it sounds like everyone here agrees on this
well keep in touch as we have the same exact bike AND problem ....also check ur spark plugs to see if theyre fouled
 

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Discussion Starter #11
well keep in touch as we have the same exact bike AND problem ....also check ur spark plugs to see if theyre fouled
alright, ill check on that tomorrow, they were replaced like 2 months ago but ill just double check to make sure
 

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The bottom line here is that if you are 100% certain that you have eliminated the "crap from fuel tank" problem and you are still leaking gas from the carbs, then you most likely need to replace the valve seat and needle in the carb. But first you should check float height because if the floats are too high, the carbs will overflow.

I should note that an often overlooked area is the petcock. Some folks will thoroughly clean the carbs and the gas tank, but not the petcock and then they wonder why the carbs got dirt in them again.
 

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WFO nailed it. For the carb to leak the fuel level is too high in the bowl. The level is set too high or the float needle valve, seat has debris or wear and is leaking. If it is leaking when the bike is not running then the vacuum operated petcock is leaking also. Dirt and debris can also collect and dry in the lines and then when the bike is now being used the dirt flakes off and travels down the lines to the furthest point. The No.1 or 4 carb. You clean tank and carbs and forget the lines between them.

You probably already know this but drain the carb bowl and collect the fuel in a container and look for debris. Then with the drain open turn on the fuel supply to try to flush the needle and seat area. Close the drain and see if the overflow stops. When you start with an empty bowl the float valve it fully open. If you start with it full, the float only opens as far as it needs to replenish the fuel drain and might not open far enough to flush the debris out. The down side is if you go to the prime position you are taking fuel from the bottom of the tank and that is where the most debris may be in the tank.
 

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Discussion Starter #14
WFO nailed it. For the carb to leak the fuel level is too high in the bowl. The level is set too high or the float needle valve, seat has debris or wear and is leaking. If it is leaking when the bike is not running then the vacuum operated petcock is leaking also. Dirt and debris can also collect and dry in the lines and then when the bike is now being used the dirt flakes off and travels down the lines to the furthest point. The No.1 or 4 carb. You clean tank and carbs and forget the lines between them.

You probably already know this but drain the carb bowl and collect the fuel in a container and look for debris. Then with the drain open turn on the fuel supply to try to flush the needle and seat area. Close the drain and see if the overflow stops. When you start with an empty bowl the float valve it fully open. If you start with it full, the float only opens as far as it needs to replenish the fuel drain and might not open far enough to flush the debris out. The down side is if you go to the prime position you are taking fuel from the bottom of the tank and that is where the most debris may be in the tank.
alright i already have a new petcock and was planning on replacing it. I'm assuming that nothing really should be clogging the carb, but i will clean everything and replace the fuel lines/vacuum lines, clean and seal the tank, and add a new fuel filter. I think the most likely reason is the float in the 4th carb float needles position is to high and never closes off the gas, Ill be checking that first to see if it fixes it.
 

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Good plan. You have a really nice, vintage bike that in my opinion is well worth spending a little and getting it back on the road. The best way to check your float height setting is with a clear flexible tube connected to your drain and held up beside the carb with the bike held vertical (on the center stand if you have one). You may have to jury-rig a tube connector that will attach to your carb float bowl drain. See generic picture below. Your manual should tell you what the proper "service fuel level" is for your bike.
41883
 

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I've been fixing up this old Kawasaki I bought that wasn't running, all I did was take of the carb and replace the jets and gaskets in the carb and float needle. I got the bike running for about a week with no real issues. Then the bike started pouring out gas in the 2nd carburetor. It was coming out of the nipple of the bottom of the float bowl. I took out the carb and there was a bit of stuff clogging the needle so i cleared that out, but the carbs back in and it stopped. Then It started doing the same thing out of the 4th carb. I took the carbs out again and cleared everything out and it still was pouring gas out. I have since cleaned all the carbs again to make sure absolutely nothing would clog them but the 4th carb still leaks gas out of the nipple at the bottom of the bowl. Anyone has any similar issues that knows what I need to do to fix it?
I have had this happen due to an old fuel line from the tank to the carbs. Little rubber bits would flake off the inside of the fuel line and stick in the float needles. Those were Keihin carbs and the picture looks like a Keihin carb. Think an 82 Kawasaki should have Mikuni carbs. I would Replace the main fuel line, tank to carbs. Check for bad "o" rings on the float bowl screws.. and check for the correct or damaged float bowl screws. Can the float bowl screws be removed?.. or are they stuck?
 

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I tried to quote you question but it didn't work for some reason. You asked if I have had the problem of fuel overflowing from the carbs. No, I haven't. Knock on wood. When you replaced the needle and seat, did you use Japanese parts? I used K&L parts made in Japan. Some cheaper stuff made elsewhere may not be as good.
 

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Discussion Starter #18
I have had this happen due to an old fuel line from the tank to the carbs. Little rubber bits would flake off the inside of the fuel line and stick in the float needles. Those were Keihin carbs and the picture looks like a Keihin carb. Think an 82 Kawasaki should have Mikuni carbs. I would Replace the main fuel line, tank to carbs. Check for bad "o" rings on the float bowl screws.. and check for the correct or damaged float bowl screws. Can the float bowl screws be removed?.. or are they stuck?
the O rings are good are checked those already, but ill replace the fuel line but I have already replaced it 5 months ago
 

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Alright, things have gotten much worse. I took out the carbs and made sure they were all clean, then i adjusted the float in the crab that was leaking to match the other floats. Then I switched the float from 4 to 3 so if it is the float carb 3 should leak gas. I got the carbs back in and fired it up. Now carb 1 and 4 both leak gas, even if the bike is being ridden. It switched from 1 to 4 randomly. The bike also can't keep a steady idle. It's either at like 500 rpm and about to kill the engine or at 5000 rpm and its starting to make the engine scream. I honestly have no clue how on earth everything has gone so wrong from such a little thing. Thats the update for the carb
 

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Normally all carb parts are kept separate from the other carbs for a number of good reasons. For instance, some bikes (including mine) actually use different main jet sizes in the middle two cylinders. You would never know that unless you noted the tiny markings on each and every jet as you took them apart. Also, because of wear and tear, the moving parts of a carb have become "married" to each other and will only work correctly if they stay married. A good example of this is your needle and needle valve. They need to stay matched. Floats are matched to the needle and needle valve so it is not a good idea to move them around.

Do I understand correctly by your first post that you replaced all of the float needles with new stock? If so, did you also replace the float needle seats?

Don't beat yourself up. Carbs are probably the most complex, most tempermental and least understood part of a motorcycle. It may be time to just walk away and take a breather for a few days or week. I do that when one of my motorcycles is testing my patience.
 
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