Gas leaking out of Carb

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CFP2
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Bikes: XLH 75 Harley Sportster
Location: Michigan

Gas leaking out of Carb

#1

Post by CFP2 » Wed Apr 22, 2009 11:28 pm

I have 75 XLH sportster with the OEM Bendix/Zenith carb. I was having some mixing issues so I rebuilt the carb with a OEM kit from J&P. The problem is after the bike stops running, gas starts leaking out of the carb. between the bowl and the carb body. I tried to tighten up the bowl but that just slowed the leak but didnt stop it. Any advice would be great.



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Re: Gas leaking out of Carb

#2

Post by panz4ever » Thu Apr 23, 2009 12:26 am

First thought would be that the float level adjustment is not properly set. When you put it back together if you flip the carb over so that the float is at the top, the bottom float surface must be 3/16 in from the carb gasket surface. Seems to me that if you shut it off and gas is still coming the float level is a primary culprit.

CFP2
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Location: Michigan

Re: Gas leaking out of Carb

#3

Post by CFP2 » Thu Apr 23, 2009 12:35 am

I will give that a shot tomorrow and report back. Thx

CFP2
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Re: Gas leaking out of Carb

#4

Post by CFP2 » Thu Apr 23, 2009 9:20 pm

I measured the distance between the float and the carb and found it to be dead on....Should i adjust it further or is there a different option?

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Re: Gas leaking out of Carb

#5

Post by hydra74 » Thu Apr 23, 2009 9:46 pm

if the float level is ok inspect the tip of the needle and the small spring on the float hinge

CFP2
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Re: Gas leaking out of Carb

#6

Post by CFP2 » Thu Apr 23, 2009 10:46 pm

I had the bowl off and the moved the float up so the pin would ingage which stopped the gas flow. Is it normal for the gas to leak through the gasket between the bowl and carb body if the bowl is too full?

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Re: Gas leaking out of Carb

#7

Post by FlatHeadSix » Thu Apr 23, 2009 11:34 pm

if the bowl is too full you can expect the leakage, but the bowl should never get full enough to do that. It will also leak from the vent if the needle valve is not seating and keeping the fuel at the correct level in the bowl. You either have a defective float or a defective needle and seat. If you lucky it may just be a speck of dirt in the seat.

keep us posted

mike

CFP2
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Re: Gas leaking out of Carb

#8

Post by CFP2 » Fri Apr 24, 2009 12:30 am

Should I adjust the float level?

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Re: Gas leaking out of Carb

#9

Post by FlatHeadSix » Fri Apr 24, 2009 1:34 am

CFP2 wrote:I measured the distance between the float and the carb and found it to be dead on....
If you raise the float manually, or turn the assembly upside down, and the float stops at the correct distance from the top of the bowl, your problem is what I said above. Either the float does NOT float anymore (its defective) or the needle does not seat firmly in its seat. Further adjustment will not fix it, you will have to replace the defective parts.

Does your needle have a rubber tip on it?, or is it solid metal? If it has a rubber tip, usually VITON, it may have been affected by additives in the fuel you are using. They swell up or deteriorate to the point where they no longer form a seal inside the valve seat. Solid metal needles may develope a groove at the point where they contact the seat and this also causes an imperfect seal, pitting or corrosion will cause the same thing. The ONLY fix is to replace them with new ones, buy the solid steel type, avoid the rubber tipped ones unless you want to constantly keep replacing them.

mike

CFP2
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Location: Michigan

Re: Gas leaking out of Carb

#10

Post by CFP2 » Fri Apr 24, 2009 1:48 am

Its a rubber tipped needle and I rebuilt my carb last month...I will check my float and take a look at my needle tip.

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