Leaky Weber 40IDA's on 911 - help!

[Dr. Ferdinand]

After a while stored in the garage I started up my '71 911T ready for the MOT.

The motor runs a PMO Weber 40IDA 3C set up.

I sensed a strong smell of petrol and found fuel to be leaking from the accelerator pump bodies on both carbs - see below



Does anyone have an ideas what the issue could be? I initially suspected diaphragm failure but this would be a massive coincidence on both carbs.

Hoping for a quick fix without removing the carbs!!

[neilbardsley]

I had this on my 40 idf webers and unfortunately it was the surface of the accelerator pump. However, strange that it's happen on both sides. Makes me think that both diaphragms has dried out. I don't think the rebuild kits are too much from webcon? Do one side and see if it sorts the problem?

(PS probably best to want for someone that knows what they are talking about to comes along)

[911hillclimber]

Are you sure the leak is from the accelerator assembly and not from above, ie the gasket line of the carb top casting?
Fuel can leak somewhere and travel along various joining faces/ridges etc before dropping under gravity of another path.

Remove the air filter housings and the carb top plate then run the engine till hot and look Very carefully. Finger rubbed around the areas works best, a wet finger is immediate.

[fetuhoe]

All of the brown discolouration is typical of a fuel leak and it looks as if this has been happening for some time.