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MG MGB Technical - carb problem

I have a 1972 mg mgb. Car idles rough. The vacumm hoses from the side of the car that eventually lead to charcoal canister are full of gas when I disconnect them. The car will run better when I disconnect them but the tubes from the carbs leak gas. Any help would be great, I am getting frustrated. Thanks
Shawn Allen

Check the condition of the diaphragm in the carb (if the have the zienth)
Thats what was causing all the problems for me.
KRS

I have the SU type HIF carbs for the previous response
Shawn Allen

Sounds like the float valves are leaking and causing a/the float chamber to overflow. Could be a random bit or dirt, disconnect the fuel pump and run the float chambers dry, then reconnect the pump with the ignition on. The resulting rush of fuel through the now wide-open valves usually flushes anything away. If it happens again straight away the valve is faulty. If it is OK for a while then happens again you could have dirty fuel from a rusting tank, check the float chamber for debris in the bottom. A leaking float can also cause this, partially full of fuel it will not float high enough to close the valve before the level of fuel reaches the overflow.

However if you have an aftermarket fuel pump these can deliver too much pressure which will overwhelm even good valves, and you need to fit a pressure reducing valve as well.
Paul Hunt 2

I had a similar condition when my carb jets worked themselves loose - constant flooding. In addition to the floats you may want to make sure your jets are tight and, if grose jets aren't fitted, inspect the condition of the rubber jet tips.
Adam Birnbaum

This thread was discussed between 17/05/2006 and 18/05/2006

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