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Why is my weber leaking


qdessa
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My carb is leaking and only seems to leak when I press the accelerator enough to engage both barrel.

I have an electric fuel pump that is using a stock ( was on the car when I got it ) fuel pressure regulator that is vacumn controlled.

The same carb was on another engine with a mechanical fuel pump and I didn't notice any leaking.

The car runs good btw.

post-2250-13667632792703_thumb.jpg

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I don't have any history on the carb. It was on the car when I bought it about 3 years ago. I put in a new motor from an e21 this year ( hence the electric fuel pump). So a rebuild is certainly something to do.

Just wondered if others had the same symptoms.

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the mechanical pump changes fuel volume delivered based on engine speed. so as the carb needs more fuel, the pump delivers more fuel. with an electric pump, even regulated, you are getting more fuel than you need, especially at lower rpms. there will be a shut off valve on the carb bowl via the float, but it seems reasonable to think that the electric pump could be putting more pressure on the gaskgets than is necessary.

Jon

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My suspicions in order:

Bad pressure regulator - these do fail and can 'overpower' the needle and float at high pressures. Cheap - replace it and make an unknown known.

Worn Shaft Bushings/bent shaft - replaceable, but likely more hassle and expense than acquiring a used 32/36 and rebuilding it.

Improper Float setting - reset.

I doubt it's the base gasket as suggested because the leak appears to be above it.

Cheers!

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the mechanical pump changes fuel volume delivered based on engine speed. so as the carb needs more fuel, the pump delivers more fuel. with an electric pump, even regulated, you are getting more fuel than you need, especially at lower rpms. there will be a shut off valve on the carb bowl via the float, but it seems reasonable to think that the electric pump could be putting more pressure on the gaskgets than is necessary.

Jon

The bowl is vented.

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