Petrol leak from Carb

[rogerm]

Hello,

I have an electric fuel pump and a Zenith NDIX carb. I started my Haflinger after several months in the garage.

The electric fuel pump continues to pump (even when the engine is not running, but ignition on) and petrol leaks out of the left side (looking from back of vehicle) of the carburetor.

I guess the float chamber valve is broken ?

Any advice welcome. (I have ordered a large fire extinguisher!)

Thanks

Roger

[AustHaflinger]

I have the same arrangement as you and run this fuel pump - https://www.ebay.com.au/itm/Electric-Ga ... 5230632fa6
Make sure your pump is only about 2-3 psi.


The standard float valve easily handles this fuel pump which does continue to run but does not have the pressure to overcome the float valve.

So I suspect you have one of two issues (or both)

1. The float valve has crud in it stopping from fully closing or it is gummed up and not closing.

2. Your floats have a hole and sink lower in the float chamber so allowing fuel to constantly flow in. The floats (there are 2) are plastic and each comprises of two halves that are glued together - as happened to me the glue can fail allowing fuel inside the float - (to test remove the float and shake you can hear the fuel inside or place the float in some hot water and squeeze slightly and you will see a stream of bubbles if there is a hole. There is not much point regluing then as firstly you need specialist glue that bonds plastic and is impervious to petrol and the weight of the glue upsets the weight of the float. Just buy new floats - I tried to fix mine and it was just too hard.

Now if you have not tinkered with anything and all worked OK previously then the float level is most likely OK. You dont need to bend anything etc on these - the float level is adjusted by removing the float valve and changing the thickness of the washer that spaces the valve out from the carb body. So doesn't go out of adjustment as such so if it was ok before leave it. I dont know how you measure the float level with the carb all assembled but my mechanic does.

Good luck with it and I hope this helps.

Garry

[heinkeljb]

As above, the Ethanol in petrol nowadays can eat through various plastics that were impervious to straight petrol before. Noticeably the petrol tank liner of years ago now starts to peel off and ends up blocking the fuel line.
If you haven't already, put another fuel filter in line between the pump and the Carb to try and catch some more of the rubbish before it gets to the Carb.
The mechanical fuel pump on a Haf is very low power, so even the sort Gary mentions above is supplying more pressure than the standard pump. You could get away with a pump delivering 1~2 psi.

John