Fuel leaking from all 4 carb overflows

[nickziemann]

Hi folks, great forum here. I purchased a 1980 CB750K in pretty clean condition a month ago.
Everything on it ran pretty great for about 3 weeks. It did have a high idle issue when the engine warmed up, so I did try adjusting the idle (only slightly though), it didn't do much. It also had a mild gas leak from 1-2 carbs when I got done from a ride, but I would just shut off the petcock.

Last week I was getting off the highway and I realized it was draining fuel from all 4 carb overflows, and it was acting like it was flooding. I pushed it home once I couldnt get it started any longer, and just today I took out the carbs and spent the day thoroughly cleaning them. I installed them back on the bike, and the same thing happened. A continuous flow of fuel from whichever 2 carbs has the most gravity on them.

This could be something simple, maybe I screwed it up by adjusting the idle, or something more severe.
Does anyone have any suggestions?
One thing I did notice was 1 of my floats has gas inside of it, so it's not floating correctly like the rest, but I couldnt imagine that being the only culprit.

Thanks in advance!

Nicholas

[TOOLS1]

Welcome to the forum. The float with gas in it definitely needs replaced. I would also suspect the others as well. I would also replace the float needles. Lastly check your float height. If your floats are too high it can cause this. These are really the only things that could cause the problems you are describing.
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[nickziemann]

Thanks a lot for taking the time to respond. When cleaning I didn't focus an extra amount of attention on the float needles, I'll give another go at it and replace the questionable parts. Thanks! 

On Jun 25, 2011, at 5:19 PM, TOOLS1 [via Honda CB750'S] wrote:

Welcome to the forum. The float with gas in it definitely needs replaced. I would also suspect the others as well. I would also replace the float needles. Lastly check your float height. If your floats are too high it can cause this. These are really the only things that could cause the problems you are describing.
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[nickziemann]

I've fixed it! Thanks! No more leaking gas, the previous owner had installed the fuel filter in reverse, so that clearly wasnt helping the issue. I do have a seperate problem which I would love advice on. The bike starts and purrs great at about 1100 rpms while idling, but once the engine warms it'll get into the 3k-4k range at stoplights, just idling. Is this a potential vacuum leak issue? Any help would be greatly appreciated, thanks! 

Nicholas 

On Jun 25, 2011, at 5:19 PM, TOOLS1 [via Honda CB750'S] wrote:

Welcome to the forum. The float with gas in it definitely needs replaced. I would also suspect the others as well. I would also replace the float needles. Lastly check your float height. If your floats are too high it can cause this. These are really the only things that could cause the problems you are describing.
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[Re-run]

It is possible but it could also just be your idle screw is turned in too far. I dont know about your carbs but mine have a fast idle adjustment. Since I have never used this, unless I keep on the gas while warming up, it dies OR I could turn int the idle knob to keep things going but when warm, the idle will be high.
I suspect the same thing of yours.

[TOOLS1]

Mine does that to. When warm it idles higher. I will just reach down, and give the screw a turn.
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