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Leaky carb 2011 yz250f 2-4 hours on engine

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Im having a small issue of fuel leakage out of the bottom most part of my carb. The fuel stops after i turn the fuel off. Its a very small leak and probably most would overlook it. It takes about 2 days to become a 2 inch diameter puddle. However, my previous 450 carb never leaked. I checked the float and the float needle valve and there is no dirt to be found that would be blocking the valve. Im still new to dirt bikes and am wondering if its just a regular thing. My bike has also been staying up in the revs after i crack the throttle on the track. I have to brake and put load on the engine to make them go down. Im not sure if this is related. I tryed messing with the fuel screw and just couldnt get the idle to come back down. After i took the carb out i put a "trackside" fuel mixture screw in so if this problem is not related ill be able to fine tune the carb a little easier.

Edited by Broody

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I had the same problem with my 2011 250f leaking it was a quick fix. Checking the float needle valve had some scuff marks and was hanging up, to check move the float up and down it should be smooth and not sticking. I just polished the needle valve up with a light scouring pad. also check your float height and tab.

See this thread; http://www.thumpertalk.com/forum/showthread.php?t=1013078

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Define 'leaky'. A few drops is normal.

a dribble, i only notice it when its on my concrete floor, the bike has about a 2 inch diameter puddle under it and this it takes about 2 days to get that big.

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Could possibly be from just putting it on the stand. When you lean it over and pick it up it may over flow slightly then drip until it dries up. Without truly knowing the severity of the issue I would recommend checking float height and all air bleeds. Is the fuel shut off when this is happening? Could be a combination of leaky shut off and leaky needle and seat. Just for a test, try turning off fuel, lean bike over to the point fuel flows out of the hose, then dry the hose and put bike on the stand to see if it persists. I don't remember any of my carbed bikes having this type of problem.

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Could possibly be from just putting it on the stand. When you lean it over and pick it up it may over flow slightly then drip until it dries up. Without truly knowing the severity of the issue I would recommend checking float height and all air bleeds. Is the fuel shut off when this is happening? Could be a combination of leaky shut off and leaky needle and seat. Just for a test, try turning off fuel, lean bike over to the point fuel flows out of the hose, then dry the hose and put bike on the stand to see if it persists. I don't remember any of my carbed bikes having this type of problem.

It stops leaking when the fuel is off. I am just concerned because it never stops when the fuel is on. Ill try checking the float level and inspect the needle to see if it sticks.

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Sounds like a problem between the float height, needle, and/or seat. Inspect the seat and needle sealing surface closely with a magnifier. Could be any small imperfection or spec causing the problem.

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Im having a small issue of fuel leakage out of the bottom most part of my carb. The fuel stops after i turn the fuel off. Its a very small leak and probably most would overlook it. It takes about 2 days to become a 2 inch diameter puddle. However, my previous 450 carb never leaked. I checked the float and the float needle valve and there is no dirt to be found that would be blocking the valve. Im still new to dirt bikes and am wondering if its just a regular thing. My bike has also been staying up in the revs after i crack the throttle on the track. I have to brake and put load on the engine to make them go down. Im not sure if this is related. I tryed messing with the fuel screw and just couldnt get the idle to come back down. After i took the carb out i put a "trackside" fuel mixture screw in so if this problem is not related ill be able to fine tune the carb a little easier.

Trace the hose that is leaking (one should be wet). I'm not familiar with your specific bike, but all have an overflow hose, and most have a drain hose. If the dribble is coming from the overflow, your float valve is leaking a bit. If it is coming from the drain, then the bowl drain screw is leaking.

Then we can figure out a fix.

JayC

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Sounds like a problem between the float height, needle, and/or seat. Inspect the seat and needle sealing surface closely with a magnifier. Could be any small imperfection or spec causing the problem.

Ya i checked the needle and its not sticking, it must be the height. It didnt act like this when i bought it. Wonder why its doing it now...probably break-in?

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Im having a small issue of fuel leakage out of the bottom most part of my carb. The fuel stops after i turn the fuel off. Its a very small leak and probably most would overlook it. It takes about 2 days to become a 2 inch diameter puddle. However, my previous 450 carb never leaked. I checked the float and the float needle valve and there is no dirt to be found that would be blocking the valve. Im still new to dirt bikes and am wondering if its just a regular thing. My bike has also been staying up in the revs after i crack the throttle on the track. I have to brake and put load on the engine to make them go down. Im not sure if this is related. I tryed messing with the fuel screw and just couldnt get the idle to come back down. After i took the carb out i put a "trackside" fuel mixture screw in so if this problem is not related ill be able to fine tune the carb a little easier.

http://www.facebook.com/#!/photo.php?fbid=330434996973866&set=a.330434753640557.96167.100000221058258&type=1&theater

Cant figure out how to insert an image on here but here is a link that shows a pic of the carb. The discolored line is the part the carb is leaking from. The very bottom of the carb.

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